human immunodeficiency virusListen to pronunciation(HYOO-mun IH-myoo-noh-deh-FIH-shun-see VY-rus)The cause of acquired immunodeficiency syndrome (AIDS). Also called HIV.More InformationHIV Infection and Cancer RiskSearch NCI's Dictionary of Cancer TermsStarts withContainsBrowse:ABCDEFGHIJKLMNOPQRSTUVWXYZ#