UNDERPANTS
underpants
(noun) an undergarment that covers the body from the waist no further than to the thighs; usually worn next to the skin
Source: WordNet® 3.1
Noun
underpants pl (plural only)
underwear covering the genitalia and often buttocks, usually going no higher than the navel.
Synonyms
• (underwear): boxers, briefs, bloomers, (UK) pants, panties, (slang) butt-huggers, undies, (slang) tighty whities, knickers, drawers, (UK, Australia) smalls, (slang, UK) shreddies, (slang, New Zealand) gruds, longjohns, thong, underwear
Source: Wiktionary