chalk

its used to describe the favorite, mostly in betting and gambling

the patriots have been the chalk in the NFL for several years

chalk

The expected outcome, especially in a sporting event. Derived from, "you can chalk that up right now, we don't even have to see it."

My NCAA sweet sixteen bracket was chalk.

chalking it

At the start of intercourse you rub the tip of your penis on the women's vagina. Also spitting on it or licking fingers and rubbing on the tip to add moisture.

I was chalking it about to nail her and she stopped me and asked what her name was.

chalk that

Forget that; nevermind that.

Chalk that exam and come to my party.

Chalk

Military term for an aircraft load. More specifically a group of airborne soldiers which deploy from a single aircraft or platoon sized unit for air-assault operations.

"I'm placing you in charge of chalk #4, soldier!"

chalk

(noun) A theory regarding a mystery. Refers to the practice of chalkboarding/whiteboarding ideas and expanding on them.
(verb) To actively theorize about said mysteries. Often used when someone is coming up with tinfoil theories.

"Man, so men and my friends were chalking about who Rey's parents might be..."

"Did you hear the chalk about Sylar and Peter Petrelli?"

"After those first teasers dropped, it was crazy how much chalk was flying around about what was going to happen in season 3 of Westworld."

Not-Chalk

The opposite of chalk

Tom: "What's that?"
Sarah: "This? Oh, this is not-chalk."