Definition of trade union congress in US English:

trade union congress

(also trades union congress)

noun

  • 1A delegate conference of trade unions; specifically the national conference of British trade unions, held annually since 1868.

  • 2(Chiefly in form Trades Union Congress) the national confederation of British trade unions, originally formed to organize the annual congress; (also) any of the equivalent organizations in other countries; abbreviated TUC.

Origin

Mid 19th century.