n.
a person who is responsible for a crime or other misdeed.
▸the cause of a problem.
Etymology
C17: orig. in the judicial formula Culprit, how will you be tried?, perh. from a misinterpretation of the written abbrev. cul. prist for Anglo-Norman Fr. Culpable: prest d'averrer notre bille ‘(You are) guilty: (We are) ready to prove our indictment’.