underwear UK /ˈʌndəwɛə/US /ˈʌndɚˌwɛɹ/ noun2 •the clothes that people put on first, which touch the body and are covered by other clothesDon't scratch and bite, my little bear, you'll soon need bigger underwear. — 1998 •Underpants (boxers, briefs, panties, etc) and often bras. formsunderwears