as a verb: to grab and tug a nipple, especially through clothing, especially roughly; in bdsm, a common way to find out if the girl you're making out with is really a sub or just playing in the scene.
I was making out with Megan and I nippled her real good while we were kissing; she started humping my leg so I knew she was one of us.
1) That precious spot in a femalebreast. Most of the times it could be brown. Males like to lick and suck on them. They also are used to feed a new born baby.
2) A nipple can also be that part of a babys drinking bottle they drink the fluids out of.
1) Man dude!! She got some big ass nipples!!
2) Look at my bro. hes been sucking all the milk outta the nipple