n 1  :  a living animal or plant on or in which a parasite lives - see DEFINITIVE HOST INTERMEDIATE HOST   2  :  the larger, stronger, or dominant one of a commensal or symbiotic pair  3 a  :  an individual into which a tissue or part is transplanted from another  b  :  an individual in whom an abnormal growth (as a cancer) is proliferating .
 
 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2004.