Merriam-Webster Collegiate Dictionary - homo

 I. noun  (plural ~s)  Usage: often capitalized  Etymology: New Latin Homin-, Homo, from Latin, human being — more at homage  Date: 1591 any of a genus (Homo) of hominids that includes modern humans (H. sapiens) and several extinct related species (as H. erectus and H. habilis)  II. noun  (plural ~s)  Etymology: by shortening  Date: 1922 often disparaging ~sexual  • ~ adjective, often disparaging