IPA: /ˈʌndərˌɡɑːrmənt/
KK: /ˈʌndərˌɡɑrmənt/
A piece of clothing that is worn underneath outer clothes, usually close to the skin.
She chose a comfortable undergarment to wear under her dress.
Undergarment → It is formed from "under-" (meaning beneath or below) and "garment" (from Old French *garment*, meaning clothing or attire). The word "undergarment" refers to clothing worn beneath outer garments.
Think of something that is worn 'beneath' ('under-') your regular clothes ('garment'). This helps you remember that an undergarment is clothing that goes underneath.