The muscle in your ass that keeps you from shitting your pants while farting or straining

In first person shooter games such as Call of Duty, people use the term "clutch".

This term is normally carried out in a game mode called Search and Destroy, where there is no respawning and whoever dies will have to sit back and wait until the rest of the players on the opposing or friendly team are eliminated.

The term "clutch" is used in situations where there is only 1 person on one team and multiple enemies on the other. This term is used when the person takes out all the multiple enemies on the opposing side.

While sitting on the toilet and having so much shit come out that you have to flush once for the poo and a second time for the toilet paper.

The tremor or involuntary quivering of your clutch foot (when you are driving stick ) and you just had a near-miss of an accident or you are being pulled off by a cop and you have drugs in your trunk or on your person. It is coursed by fear.

1. Someone who cant drive a car with any type of control.
2. A person who cant work the clutch of a car, and always ends up stalling.
3. Most of the time a clutch fuck is someone who didnt pass drivers education and just woulde like to drive a car

Used on an episode of mad TV, it is a synnonym of/for
the bomb, cool, sweet, the shit, awesome, dank, clutch, HxCore, badass, etc.

1.

SIA is basically a Gaming term in computer world, refering to real life term - KIA.

It's very alike with word skillad, meaning Skilled In Action. It's Killing with Skill = S-killing.

Being SIA in first person shooters has a meaning of being shot in a very unorthodox, very thought through and amazing way.
SIA can be anything including Headshots, Clutches, ACEs, and other amazing stuff that can be done using skill.

2.

SIA'd also may have a meaning of " Served in action " linking to " you got served " .