1340, "doing no evil, free from sin or guilt," from O.Fr. innocent (11c.), from L. innocentem (nom. innocens) "not guilty, harmless, blameless," from in- "not" + nocentem (nom. nocens), prp. of nocere "to harm" (see noxious). Meaning "free from guilt of a crime or charge" is from 1382. The earliest use was as a noun, "person who is innocent of sin or evil" (c.1200).