Adulter

Part of speech: noun

Definitions

1. A person who engages in extramarital sexual relations while being married to someone else
2. an individual who violates the sexual fidelity expected in a marital relationship
3. one who participates in infidelity, breaching the trust established in a committed partnership

Etymology: The Latin "adulter" meant "adulterer" in the most literal sense: a man who had sexual relations with someone else's wife. It is built from "ad-", "to" or "toward", and "alter", "other", so its core idea is "one who goes toward another (person's bed)." The corresponding verb, "adulterare", meant to commit adultery, and it could also mean to tamper with or corrupt something, which is the sense that gave English its related "adulterate." English borrowed the noun directly from Latin, so the word arrived with its original meaning intact. The form is a plain Latin agent noun, and nothing in its history involves a sound shift or an unexpected change of sense, so the main point to take from it is how transparently the Latin parts describe the act.