Black's Law Dictionary (2nd edition)dictionaries

Trade Union

A combination or as-soclation of men employed in the same trade, (Usually a manual or mechanical trade,) unlt-ed for the purpose of regulatlng the customs and- standards of their trade, fixing prices or hours of labor, influencing the relations ef employer and employed, enlarging or main-tainlng their rights and privileges, and other similar ■ objects

Source: Black's Law Dictionary 2nd Ed (1910)