bidet UK /ˈbiːdeɪ/US /bɪˈdeɪ/ noun2 •A low-mounted plumbing fixture or type of sink intended for washing the external genitalia and the anus. •(no longer used) A small horse formerly allowed to each trooper or dragoon for carrying his baggage.For joy of which I will return to myself, mount my bidet in a dance — 1631 formsbidets