The Collaborative International Dictionary
kainozoic
Cenozoic \Ce`no*zo"ic\, a. [Gr. ? recent + ? life.] (Geol.) Belonging to the most recent division of geological time, including the tertiary, or Age of mammals, and the Quaternary, or Age of man. [Written also c[ae]nozoic, cainozoic, kainozoic.] See Geology.
Note: This word is used by many authors as synonymous with Tertiary, the Quaternary Age not being included.
Wiktionary
kainozoic
a. (alternative form of Cenozoic English)