If you were looking for the book of the same name, it'd be here.

Xenocide is the act of wiping out an entire sentient alien species. Thus years after the Third Invasion, it was referred to as the "War of Xenocide ", for the humans thought all of the Buggers in the universe were wiped out, and regretted the fact. Admiral Bobby Lands attempted a Xenocide on the Pequeninos.