to organize (workers) into a trade union to join or cause to join a trade union - (transitive)
to subject to the rules or codes of a trade union
WordReference Random House Learner's Dictionary of American English © 2026
un•ion•ize /ˈyunyəˌnaɪz/USA pronunciation
v., -ized, -iz•ing.
WordReference Random House Unabridged Dictionary of American English © 2026- Businessto organize (workers) into a labor union: [~ + object]to unionize the workers.[no object]The workers unionized.
un•ion•ize
(yo̅o̅n′yə nīz′),USA pronunciation v., -ized, -iz•ing.
v.t.
v.i.
un′ion•i•za′tion, n.
un′ion•iz′er, n.
v.t.
- Businessto form into a union.
- Businessto organize into a labor union;
bring into or incorporate in a labor union. - Businessto subject to the rules of a labor union.
v.i.
- Businessto form a union.
- Businessto join in a labor union.
- union + -ize 1835–45
un′ion•iz′er, n.
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