From The Collaborative International Dictionary of English v.0.48 :
Hybridization \Hy`brid*i*za"tion\, n. The act of hybridizing, or the state of being hybridized. [1913 Webster]From WordNet (r) 3.0 (2006) :
hybridization n 1: (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids [syn: hybridization, hybridisation, crossbreeding, crossing, cross, interbreeding, hybridizing]