I've been thinking about listing some of these, because it actually was first yesterday I got a better idea about what "mix-up" actually meant. 
People throw these term around as if it's common knowledge. 
Feel free to correct me. I'm just writing down what my understanding is. 
 
Mix-up:
A characters ability to leave the opponent guessing about high/low/mid attacks.

Juggling:
Keeping the opponent in the air for combos. 
 
Chain Combo: 
A combo that's build into the game. It's the combo's you can find on the move-list. 
 
Custom Combo:
A combo that's not in the move-list. 
 
Launcher:
A move that get the opponent up in the air - leaving them open for follow-up attacks. 
 
Pop-up attack: 
A move that knocks the opponent into the ground so they bounce - effectively launching them in the air leaving them open for follow-up attacks. 
Technically I don't know if these attacks are any different than launchers except through how they animate. 
 
Nerf:
Term used about making a character or move weaker through a patch. 
 
Buff:
Term used about making a character or move stronger through a patch. 

Rush-down:
I think it's a characters ability to quickly close the distance to the opponent while continually attacking - thus keeping up pressure. 
I'm not too sure about this one. 
 
Zoning:
Keeping your opponent at a distance that is advantageous to your characters move-set.
  
Whiffing:
When a move doesn't connect.
 
Chip-damage: 
I believe it refers to the small amount of damage received when blocking. 
 
Wake-Up: 
While recovering from a knock down you have an opportunity to attack as you "wake-up". 
The strategy/usefulness of wake-up attacks depends on your fighter's move-set.

Combo Breaker: 
A technical ability to stop the opponents combo. The use of this ability is usually is usually limited to certain requirements of uses (example: In Mortal Kombat you have to use 2 bars from the the EX Meter to preform a Combo Breaker). Other games will let you preform special moves to break a combo. Combo Breaker is also a meme from Killer Instinct. 


Terms I'm really not sure about what actually means: 
 
Option-select
Not quite sure what this means - but it get used quite often. 
It's perhaps something to do with a move that has some different follow-up moves - Or it has something to do with canceling out of a moves animation.
 
EDIT: 
A link provided by @groin pretty much makes this thread unnecessary: 
 
  @groin said:

This is an extensive list of fighting game terms: http://www.option-select.com/strategy/article/?a=12

OTG / Bound:

Zoner is also a term used, I believe this one means they can keep you at a distance, spamming noobs are one, but rush down like Johnny Cage can usually handle it lol

Zoner is also a term used, I believe this one means they can keep you at a distance, spamming noobs are one, but rush down like Johnny Cage can usually handle it lol

I just played online a bit and was just reminded of another common turned -  while I got increasingly frustrated at myself. 
 
Whiffing:
Failing to execute the intended move - and instead do some random move. 
 
Actually it's my main annoyance in online matches... And there is really no-one to blame other than myself... it sucks. 
 
Edit: apparently that's not the what the term means.

Whiffing is when the move doesn't connect

@Pessh:  Ok thanks.. Any term that covers what I described - because I honestly thought that was the term?

Edit: wrong thread

Pop-up attack: 
A move that knocks the opponent into the ground so they bounce - effectively launching them in the air leaving them open for follow-up attacks. 
Technically I don't know if these attacks are any different than launchers except through how they animate. 
 

This is an extensive list of fighting game terms: http://www.option-select.com/strategy/article/?a=12

Handy list. Here's my contribution:
 
Wake-Up: While recovering from a knock down you have an opportunity to attack as you "wake-up". The strategy/usefulness of wake-up attacks depends on your fighter's move-set.

Footsies are another one too, i do this one a lot lol

Combo Breaker: A technical ability to stop the opponents combo. The use of this ability is usually is usually limited to certain requirements of uses (example: In Mortal Kombat you have to use 2 bars from the the EX Meter to preform a Combo Breaker). Other games will let you preform special moves to break a combo. Combo Breaker is also a meme from Killer Instinct.

Zoning is the ability to control the spacing and position of your opponent.

@groin said:

This is an extensive list of fighting game terms: http://www.option-select.com/strategy/article/?a=12

This is a great tool!

Zoning is the ability to control the spacing and position of your opponent.

This is an extensive list of fighting game terms: http://www.option-select.com/strategy/article/?a=12

Footsies are another one too, i do this one a lot lol

There is only one term that matters

Salty.

There is only one term that matters

Salty.

@TechHits:  I'm not sure I quite understand. Does it mean hitting someone who's lying on the ground - and is that something that occurs in MK?

@EvilDingo said:

Pop-up attack: 
A move that knocks the opponent into the ground so they bounce - effectively launching them in the air leaving them open for follow-up attacks. 
Technically I don't know if these attacks are any different than launchers except through how they animate. 
 

Not gonna say I'm an expert, but I think the point of making a difference between launchers and pop-ups is that games tend to have rules that separates how many launch attacks and ground-bounces that are allowed within a single custom combo. So in order to reach max amount of juggles you need to alternate between the two instead of just repeating the same launch over and over.

@xhavoc86 said:

@OneManX said:

There is only one term that matters

Salty.

YES! yesss oh god yes!!! PJSalt PJSalt PJSalt

I hope you guys saw that dude in the crowd during the EVO MK Grand Finals with that giant salt shaker.

Magical.