Wiktionary
n. that part of a woman's pubic region not covered by a swimsuit; normally shaved or waxed free of pubic hair
Usage examples of "bikini line".
Unlike the hair on her head, her pubes were jet black with only a few gray strands, neatly trimmed along her bikini line.
No, she was naked: that milky rift was simply the phantom of her bikini line.
She probably doesn't even go to the bathroom, or have to wax her bikini line, Lorell thought despondently.
This girl that's my partner, Hilary, she wants me to do her bikini line.
However, when Stephanie started making noises about my bikini line, I pointed out quickly that when I wore the suit she'd picked out, plus panty hose and all the other junk designed to mold me into an acceptable shape, nobody was going to have any opportunity to inspect that hair.
Then you might watch her tweezing her eyebrows, waxing her bikini line, washing her underwear.