The word "unauthorized" is built upon the core concept of an "author," tracing back to the Latin auctor, meaning an originator or source of authority. The suffix "-ize" transforms this noun into a verb, "authorize," meaning to give official power or permission. The past participle "-ed" then creates the adjective "authorized," describing something that has been granted such power. Finally, the Old English negative prefix "un-" is attached to negate the entire concept, resulting in the modern meaning of something done without official sanction or approval. This construction elegantly layers negation onto a process of granting power, directly reflecting its legal and formal implications.

Structure: un (not) + author (originator, source) + ized (made into, characterized by) - un: A prefix of Germanic origin (Old English un-), meaning "not." It functions as a negative particle. - author: A root from Latin auctor (originator, promoter, founder), via Old French autor. In this compound, it signifies the source of authority or permission. - ized: A suffix from Greek -izein via Latin -izare and French -iser, forming verbs meaning "to render, make, or become." Here, in its participial adjective form, it means "made" or "characterized by."