See also: buttondown English A shirt with a button-down collar. Alternative forms buttoned-down Pronunciation Audio (General Australian):(file) Adjective button-down Of a collar, able to be buttoned down to the shirt, as over a necktie. (idiomatic) Serious; staid; businesslike. (idiomatic) Conservative; conventional; unimaginative. Noun button-down (plural button-downs) A shirt with a button-down collar 2011, Dan McNeil, “Doesn't take long for Guillen to be irrelevant in Chicago”, in Chicago Tribune:Wearing a stylish pink button-down with white pinstripes, Ozzie Guillen beamed about feeling like he had "come home" when he was presented Wednesday as the manager of the Miami Marlins. Wikiwand - on Seamless Wikipedia browsing. On steroids.