"small underwear" in the Italian language. Such as a thong, bikini briefs.
As the wind lifted her skirt, I saw her mutandine (not to mention, her tampon string).
Italian for little underwear. Usually refers to items which are scanty, a bra which doesn't cover much, panties which are barely there.
As she undressed I noticed her mutandine. She wore a bra which barely covered her nipples, and french-cut briefs with a waist so low that she had to shave her pubes.