D defs.my
Entry 1 sense Webster, 1913

trades union

/trādz yo͞on'-yən/ · trades· un·ion · IPA
01 An organized combination among workmen for the purpose of maintaining their rights, privileges, and interests with respect to wages, hours …
  1. 1.
    An organized combination among workmen for the purpose of maintaining their rights, privileges, and interests with respect to wages, hours of labor, customs, etc.