tighty-whities

[ tahy-tee-hwahy-teez, wahy-teez ]
/ ˈtaɪ ti-ˈʰwaɪ tiz, ˈwaɪ tiz /

plural noun Slang.

men’s white, close-fitting underpants or briefs.

Origin of tighty-whities

First recorded in 1930–35; tight + -y2 + whit(e) + -y2 + -s3