censor (n.) Look up censor at Dictionary.com
1530s, "Roman magistrate who took censuses and oversaw public morals," from Middle French censor and directly from Latin censor, from censere "to appraise, value, judge," from PIE root *kens- "speak solemnly, announce" (cognates: Sanskrit śamsati "recites, praises," śasa "song of praise").

There were two of them at a time in classical times, usually patricians, and they also had charge of public finances and public works. Transferred sense of "officious judge of morals and conduct" in English is from 1590s. Roman censor also had a transferred sense of "a severe judge; a rigid moralist; a censurer." Of books, plays (later films, etc.), 1640s. By the early decades of the 19c. the meaning of the English word had shaded into "state agent charged with suppression of speech or published matter deemed politically subversive." Related: Censorial.
censor (v.) Look up censor at Dictionary.com
1833 of media, from censor (n.). Related: Censored; censoring.