anomaly

An anomaly is something uneven or out of line with what is expected. English took the word through Latin anōmalia, borrowed from Ancient Greek ἀνωμαλία, meaning “irregularity” or “unevenness.” Greek formed that noun from ἀνώμαλος, “irregular, uneven,” and the suffix -ία. The Latin noun is recorded in Aulus Gellius around 177 CE, and its sense of irregularity carries into English, where the word can describe anything from an unexpected measurement to a departure from a rule.