to join up or be included with a group or party.
I've decided to kick in with the skinheads!
You wanna kick in with joe and fuck up that kid?
The moment you start to notice the drugs take effect.
-"those shrooms took an hour to kick in, I was starting to think I got ripped off and felt stupid for willingly eating cow turd".
-"Op op op! I think that wasabi pea is starting to kick in!".
-"I got all kinds of dibbles on me, guaranteed to kick in within 15 minutes or less! or your money back! call right now and you'll even receive a free lap dance! (tips not included, we are not responsible for clothes stains)".