underpants

[uhn-der-pants] /ˈʌn dərˌpænts/
noun, (used with a plural verb)
1.
drawers or shorts worn under outer clothing, usually next to the skin.
Origin
1920-25; under- + pants
British Dictionary definitions for underpants

underpants

/ˈʌndəˌpænts/
plural noun
1.
a man's undergarment covering the body from the waist or hips to the top of the thighs or knees Often shortened to pants
Word Origin and History for underpants
n.

1931, from under + pants. Drove out drawers, knickers in this sense.