The Collaborative International Dictionary of English v.0.48:

AFL-CIO \AFL-CIO\ [acronym.]
   the combined organizations of the American Federation of
   Labor and Congress of Industrial Organizations.
   [PJC.]

WordNet (r) 3.0 (2006):

AFL-CIO
    n 1: the largest federation of North American labor unions;
         formed in 1955 [syn: American Federation of Labor and
         Congress of Industrial Organizations, AFL-CIO]