How Well Do You Know English Slang?
mid-14c., confourmen, from Old French conformer "conform (to), agree (to), make or be similar, be agreeable" (13c.), from Latin conformare "to fashion, to form, to shape; educate; modify," from com- "together" (see com-) + formare "to form" (see form (v.)).
Sense of "to comply with the usages of the Church of England" is from 1610s; hence conformist (1630s), opposed to non-conformist or dissenter. Related: Conformance; conformed; conforming.