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Jab, Strong, Fierce

Old names for LP, MP and HP

Short, Forward, Roundhouse

Old names for LK, MK and HK

Cancel buffering

Whiffing a normal attack in front of you, and inputting another attack as a cancel afterwards. When your attack whiffs, nothing further happens, but if your opponent accidentally runs into the attack, the cancel happens automatically. This is a very common option select that will really help you get more mileage out of your strong pokes, and you don't have to take any extra risk! You just do the same inputs and let the game take the correct action based on what your opponent does.

Most often used with crouch MK xx SA3 or crouch HP xx SA3

Target combo

A character-specific attack that lets a normal cancel into another, different normal. Some target combos go on for longer too, sometimes stringing together 3 or 4 normals into a long attack sequence. It's important to note these are specifically programmed to only certain characters, and often appear in their move lists as a unique ability.

Ken's target combo is close MP > close HP

Crouch tech

A technique in some games where you try to tech a throw while you are crouching, and if a throw never comes, your tech attempt becomes a relatively low risk crouching normal instead. This only works in a few games though, since many modern games will simply force you to whiff a throw if you try to tech, even if you are crouching. Street Fighter IV is the most famous example of a game where crouch teching (and other throw tech option selects, like four finger teching) is a very common defensive strategy.

Delay tech

Trying to defend against being thrown by inputting a throw tech a little late on purpose. Delayed tech (also called "late tech") is an option select; you want to try and block in case they attack, and if they throw, pressing the buttons slightly late means you will still successfully throw tech, since the window for teching throws can be a little bigger.
This is one of the first defensive techniques new players should learn if they are playing a Street Fighter-like game, since it lets them defend against basic attacks and basic throws at the same time. Powerful stuff! It's not foolproof though — once you get into intermediate play, a player can just slightly delay their own attack to counter hit your late tech attempt. But when your opponent hesitates like this, that can open up other ways for you to defend too! You'll start to see the mind games of offense and defense when you get good at stuff like this, but start with delayed techs first!

Guard jump

On wake-up, there's 6 frames of throw invulnerability. If you block for 6 frames, input a jump and go back to blocking you will block meaties and jump throws.

Meaty

An attack that hits an opponent on the very first frame possible after they rise from a knockdown (or other similar situations, like being flipped out). This guarantees the opponent must either block the attack, or immediately do an invincible move (like a dragon punch). If they just press any random button, they will get counter hit because their attack still has to go through its non-hitting startup, but your attack is already active on top of them. Learning how to time a meaty is extremely important to fighting game strategy, and you can often just beat beginners by meatying them over and over as they insist on attacking at all times.

Shimmy

Tricking someone into thinking you're going to throw them by walking close, and then, at the last second, walking backwards out of range so they whiff a throw tech attempt like a dummy. You can then pummel them with a huge punish.

Crouch tech makes this less effective.

Hit confirm

Performing an attack, seeing that your attack successfully hit, and then reacting to this information by continuing the combo. That is to say, you "confirm" that your first attack hit before you launch further attacks, and if the attack was blocked instead, you stop and don't follow through with anything else. This is important because, usually, you will be canceling into a move that would be unsafe if it was blocked, so you only want to do it if it won't get you killed.

You can look at the score to confirm. It updates 1 frame earlier than the life bar.

Option Select

Also known as: OS

A situation where performing the same inputs can lead to several different outcomes depending on how the characters interact. Often abbreviated as "OS". A common option select is the buffer: press a normal attack and then try to cancel into a special. If you do this from far away, the normal attack will whiff and your special cancel does nothing. However, if your opponent gets hit by your attack, the special cancel will work automatically, without any extra thought or changes to the input on your part.
Good option selects tend to reduce the burden on a player to perfectly predict or react to everything happening in the game. You can perform one set of inputs, and the game will "select an option" automatically depending on what the other character did. Some OSes are common enough that we even give them names: delayed tech (try to block and throw tech), safe jumps (try to attack and block), and fuzzy guard (try to block multiple directions) are all specific examples of option selects that will help the player cover multiple choices at the same time.

Safe jumps are not really a thing in 3S due to parry

Frame trap

Two attacks back-to-back that leave a very small gap between them. The gap will be shorter than the defender's fastest attack, which means if they try to attack with a normal, they will get counter hit. Finding effective frame traps requires some basic understanding of frame data (or finding a good Youtube tutorial that has done the work for you!); you'll usually be looking for an attack that is plus on block, which lets you attack before your opponent afterwards, then swinging with a fast attack that "traps" your opponent who foolishly thought they could swing themselves.

Frame traps aren't foolproof, though. You can usually just continue to block and be fine until your opponent gets pushed out of range. Or, if you're feeling risky, you can try to get through the opponent's attack with an invincible reversal, which doesn't care about your opponent's pesky frame advantage.

Chip Damage

Damage dealt to a character while they are blocking. Most special moves will deal chip damage when blocked; the amount varies by game, but it is usually between 10-25% of the move's regular damage. Many games let you K.O. an opponent via chip damage, although Street Fighter V is a notable modern day exception. Street Fighter Alpha 3 tried to scold players who performed chip damage KOs by flashing "Cheap!" on the screen, but nobody actually felt bad about it.

Poke

An attack that's thrown out to occupy the space in front of you and remind your opponent not to try and come closer. Usually, this is a far-reaching and safe normal move with little risk. Pokes are often used to harass your opponent into doing something stupid, not unlike prodding a bear with a stick. If you use a poke to hit your opponent's poke, that's called a "counter poke".

Whiff punish

A particular kind of punish that will hit an opponent after they have whiffed an attack, and are left recovering in the open. Some whiff punishes are possible on reaction, if the attack has lots of recovery or you have a strong read on when your opponent will try to attack. At other times, if you stand at a good range and use strong pokes, you can whiff punish fast attacks without needing a reaction. Whiff punishing is one aspect of playing footsies; walk closer to your opponent so they think it's fine to attack, then walk backwards and watch them swing and miss like a dummy.

Tick throw

Making someone block a fast, close-range normal and then immediately throwing them. This is often a good strategy because light normals are usually plus when blocked, and you won't get pushed very far away after, so following up with a throw is a strong offensive option. Since the quick switch between attacking and throwing can be pretty difficult to stop sometimes, tick throws are particularly effective against beginners. Learning to defend against them (for example, by using delayed tech) might save a few controllers from being tossed against a wall.

1 frame link

A link that only has a 1-frame window to succeed, the smallest possible time interval in a fighting game. You'll know you have a 1-frame link on your hands if the on hit advantage number for your first move matches the startup number for the second move (for example, a +5 on hit attack linking into a move that hits on the 5th frame).

Piano

Pressing multiple different buttons in a row in rapid succession, often by "drumming" or "sliding" your fingers across the buttons of an arcade stick. It looks a bit like double tapping, except none of the buttons are the same and, generally, you're planning to hit all three punches or all three kicks in ascending or descending order.
You can use this technique to input special moves with rapid fire commands, like Honda's Hundred Hand Slap, or use it to get multiple chances for a super move to come out. This is particularly common in SFIII: 3rd Strike, a game where several characters regularly use tight links to combo into super. In these cases, using a piano input will try to execute the super on several consecutive frames and really increases the chances that you'll get the combo to work.

DED OS

A specific option select made famous in SFIII: 3rd Strike where a super only comes out if you build enough meter on the preceding attack. In 3rd Strike (and most fighting games), attacks that hit will earn more super meter than attacks that are blocked. Let's leverage this effect to do something cool.
First, you'll need to have 0 bars of super meter, and be very close to building your first bar; the exact amount is kind of a sweet spot that you'll recognize with enough practice. Then, armed with this precise amount of meter, get near the opponent and cancel your favorite normal directly into super without thinking or hit confirming. If your normal hits, you will build enough meter to earn a super, and it will automatically be executed. If it's blocked, you won't earn enough meter, and nothing will happen. Using this, you can pull off seemingly inhuman reactions and impress your friends. A Japanese player named DED popularized this technique, and similar to other terms, being good at something tends to attach your name to it.

Quarter Circle

Also known as: QCF

A motion used to input many common special moves that starts at down and moves in a circular motion, ending at left or right. The version towards your opponent is down, down-forward, forward, or 236 in numpad notation. It's commonly abbreviated QCF for "quarter circle forward", or maybe just called "fireball", since the vast majority of fireballs use this command. Similarly, down, down-back, back, or 214, is called QCB for "quarter circle back", and commonly referred to as the "tatsu" input, since it matches Ryu's Tatsumaki special move.

Okizeme

Also known as: Oki

The moment during a fighting game when your opponent is knocked down and you get to attack them as they stand back up. The defender's options are limited, so the offensive player gets to attack with all sorts of mixups or apply any mind game they choose. Some options include attacking with a basic meaty, doing a cross-up, or trying to bait their opponent's desperate dragon punch by simply doing nothing and blocking.
Okizeme (pronounced oh-kee-zeh-meh and often shortened to "oki") means "wake up offense" in Japanese, so the term mostly focuses on the offensive choices. If you hear someone ask "what's the oki going to be?", they are wondering what method of attack (or non-attack) the offensive player will choose to assert their advantage. It's closely related to the term wakeup, although that tends to focus more on the defensive choices (you might hear "I can't believe they did a wakeup DP!").
If someone asks "do I get oki after this move?", they're asking whether that move leaves them close enough, and with enough time, to threaten multiple different offensive options. Moves that "don't give you oki" will leave you far away and mostly end your offensive pressure.