D defs.my
Entry 1 sense Webster, 1913

Bah

/bä/ · IPA /bæ/
01 interj. An exclamation expressive of extreme contempt.
  1. 1.
    An exclamation expressive of extreme contempt.
    “Twenty-five years ago the vile ejaculation, Bah! was utterly unknown to the English public.” De Quincey.