check valve

Refers to a careful inspection of the positioning/operation of a new/replacement one-way flow-stopper to make sure it's being installed in the correct "direction".

Zero was too stupid/unaware/forgetful to perform a "check valve" detail when hooking up the plumbing for the Camp Swampy mess hall, and so now there are geysers squirtiin' up all over da camp, but no water coming out in any of the kitchen-faucets --- just something more for Sarge to bellow about.

Put in check

To put someone in their place.

"Some people just need to be put in check."

Diet Check

Winn Dixie brand Dr. Pepper

"Hey mom, did you get some Diet Check from Winn Dixie?"

Checking the oil

You delinquently lift up the clitoral hood then proceed to aggressively lick the pussy until she squirts.

I was checking the oil on your mom last night.

Checking the Oil

In football when while in the dog pile you grab and twist and/or rip, someone's dick on the opposite team.

I don't know why they're so mad coach all I did was check their oil ( i.e. checking the oil).

sperm check

When another man points out a piece of food and/or thick sauce on another mans face. Usually around the lips.

Alex walks in with a bit of ranch on his lips
Bill, "Sperm Check."
*Alex quickly wipes ranch from lips*

Check tuesday

A word used by the popular madden streamer named sketch.

Sketch: check tuesday, check Tuesday brother! Special teams, special plays, special players.

Person: whatsup brother 👦☝️