when you're wearing a shirt with out a bra and your nip slips out and you can see it and the public is like "WTF, YOUR NIP IS OUT!"
dude your nip is out, wtf its a nipslip.
When a braless female's nipple
accidentaly slips out from under a loose-fitting garment
Hold up, pause it there. Yup, total nip slip!
When a nipple
slips in to view.
She walked out on stage with her tit falling out, it was a hell of a nip slip!
When a nipple (more often than not, the nipple of a woman) slips out of an article of clothing, partially or fully, and is noticed by someone else.
She destroyed the nip slip photograph almost immediately
When a female celebrity "accidently" lets her nipple show or has her whole boob slip out. Check pictures of Lindsey Lohan.
Wow,nice nip slip!
short for "nippleslip". When a female nipple or at least the areola is showing, its called a nipslip.
Paris Hiltons nipple showed again, she had a nipslip.
Seriously. Has nobody ever told these brainless celebrity twats that there exists a garment called BRASSIERE? What kinds of exhibitionist morons go around wearing clothes which might reveal a private body part at any given moment, anyway?
Tara Reid: your nipple is ugly.