frock
Pronunciation: /frɒk/
noun
chiefly British- 2a loose outer garment, in particular:
- a long gown with flowing sleeves worn by monks, priests, or clergy: the chaplain tottered in stiff splendid frocks
- historical an agricultural worker’s smock; a smock-frock.
- short for frock coat.
- archaic a woollen jersey worn by sailors: his Cornish-knit frock

Origin:
late Middle English: from Old French froc, of Germanic origin. The sense 'priest's or monk's gown' is preserved in defrock