Own up to is an idiom that means to ADMIT or confess to something, usually a mistake or wrongdoing. The crossword solutions for this term are ADMIT (5 letters), AVOW (4 letters), and FESS (4 letters). ADMIT is a verb meaning to acknowledge or accept responsibility for something, while AVOW is a verb meaning to declare or affirm openly and strongly. Fess is a slang term derived from the word confess, which means to ADMIT to a wrongdoing or mistake.