The term UNDERWIRE is often associated with a type of bra, which is indicated by the crossword solution BRA (3 letters). Underwire bras are designed to provide extra support and lift to the bust area. They are constructed with a thin, semi-rigid wire that runs along the underside of the cups, providing additional structure and support. Underwire bras are popular among women who have larger busts, as they provide more support than traditional bras.