Endotherm: An endotherm is a warm-blooded animal (such as homo sapiens). Another term for us warm-blooded creatures is homeotherm.
An endotherm or homeotherm is as opposed to a poikilotherm (an organism such as a frog that is cold-blooded) and a stenotherm (a creature that can only survive only within a very narrow temperature range).
Endotherm is entirely Greek (as to origin). The Greek "endo-" means "within" + "-therm" is from the Greek "therme" meaning "heat" = the heat within.