IPA: /ˈʌndəwɛə/
KK: /ˈʌndərˌwɛr/
Clothing that is worn beneath outer clothes, usually in direct contact with the skin.
I bought some new underwear for the trip.
Underwear → It is formed from "under" (from Old English "under", meaning beneath or below) and "wear" (from Old English "werian", meaning to carry or to wear). The word "underwear" refers to clothing worn beneath outer garments.
Think of clothing that is worn 'beneath' ('under') other clothes — that's what underwear means.