The Collaborative International Dictionary of English v.0.48:
mutagenesis \mu`ta*gen"e*sis\ (m[=u]`t[.a]*j[e^]n"[-e]*s[i^]s), n. the causing of a mutation or the occurrence of a mutation[3]. [PJC]WordNet (r) 3.0 (2006):
mutagenesis n 1: an event capable of causing a mutation