Pronunciation: (hō'mō i-rek'tus),[key] 1. an extinct species of the human lineage, formerly known as Pithecanthropus erectus, having upright stature and a well-evolved postcranial skeleton, but with a smallish brain, low forehead, and protruding face. See illus. under hominid. 2. a fossil belonging to this species. Cf. Arago man, Java man, Peking man.