Merriam-Webster's Collegiate® Dictionary, 11th Edition
FROCK
I. noun
Etymology: Middle English frok, from Anglo-French froc, of Germanic origin; akin to Old High German hroch mantle, coat
Date: 14th century
an outer garment worn by monks and friars ; habit , an outer garment worn chiefly by men:, a long loose mantle, a workman's outer shirt, a woolen jersey worn especially by sailors, a woman's dress,
II. transitive verb
Date: 1828
to clothe in a frock, to make a cleric of