verb (used with object), un·ion·ized, un·ion·iz·ing.
- to form into a union.
- to organize into a labor union; bring into or incorporate in a labor union.
- to subject to the rules of a labor union.
verb (used without object), un·ion·ized, un·ion·iz·ing.
- to form a union.
- to join in a labor union.
verb
- to organize (workers) into a trade union
- to join or cause to join a trade union
- (tr) to subject to the rules or codes of a trade union
- to join or become joined in marriage or civil partnership
v.“make into a union,” 1841, from union + -ize. Related: Unionized; unionizing.