mid-15c., "un-ecclesiastical, secular," from Old French profane (12c.) and directly from Latin profanus "unholy, not consecrated," according to Barnhart from pro fano "not admitted into the temple (with the initiates)," literally "out in front of the temple," from pro "before" (from PIE root *per- (1) "forward," hence "in front of, before") + fano, ablative of fanum "temple" (from PIE root *dhes-, forming words for religious concepts). Sense of "unholy, polluted" is recorded from c. 1500. Related: Profanely.