To do something one time, either just because or because you had to. When you choose to abstain, but say fuck it anyway. Turn up!!!
Fuckboi stay typing that bs online. Every time I give him a taste of his own medicine he plays the victim and they want me to feel like the “bad guy”. I had to fuck him up for the one time.
Doing something just to try it, even if you only do it once and never again; for the sake of adventure.
"Dude let's try it, one time for the one time." #YOLO
...you know, when you did that that one thing.
James: "Remember that one time?"
Robert: "You mean when we did that one thing?"
James: "Yeah!"
The police. So called because you look one time at them, as doing a double-take might attract attention.
See Sir Mix-a-Lot's song "One Time's Got No Case".
The cops. It's correct that it means looking more than once can draw attention. But the actual phrase comes from someone saying "one time" to let the other passengers or friends know that they have now seen the cops and are claiming the first look, and no one else should now turn around because two or more people looking increase your odds of being stopped by more than 50%.
"One time, man. Don't turn around!"
Amongst other terms, the polite thing to yell when you see a cop cruising around, especially slowly.
"One-time! One-time!" (Then walk briskly in the opposite direction.)