Can be used in various ways, revolving around the notion of getting jacked at your nearest closet-homosexual gym. Used by meatheads, ex-'roid users, or those who suckle the teet of Whey and Protein daily.
Relationships: "I hope you know being my gains partner also means being my anal companion."
Social Functions: "Dude, after you finish giving me dome let's get some gains in!"
Bill: "How are your Gainsical studies coming along?"
Mark: "They are off the chain! I have a new squat and deadlift PR! Will you bend over and let me celebrate in your butthole?"