Unauthorise

Part of speech: verb

Definitions

1. To revoke or withdraw official permission or approval previously granted; to invalidate or cancel authorization that enabled action or access
2. To remove granted rights or permissions from an individual or entity, rendering previous approval null and preventing any further authorized operations
3. To annul or rescind the consent previously given, thereby forbidding engagement in activities once permitted or recognized as lawful or sanctioned

Etymology: "Unauthorise" is a plain formation: the prefix "un-", meaning "reverse or undo", attached to "authorise", the verb meaning to give official permission. Its sense is therefore literal: to take back a permission that has already been granted. English has long paired the two, so "unauthorise" follows the same pattern as "unlock" or "undo", where the prefix reverses the action of the base verb rather than negating an adjective. "Authorise" itself came into English in the late 14th or 15th century, from Old French "autoriser", which in turn derives from Latin "auctorizare", meaning to give authority to, from "auctor", author or originator. The author's sense of "source of authority" thus sits at the root of the verb, and "unauthorise" reverses that grant of authority. Because "unauthorise" is a later, derived formation, dictionaries record it less consistently than the base verb, and "unauthorize" with a "z" spelling is common in American usage.

Synonyms: revoke, cancel, withdraw, invalidate

Antonyms: authorize, permit, approve, allow