designating or of a Middle Paleolithic culture, associated with the Neanderthal cave people and characterized by the use of flaked hand axes, scrapers, etc.
See Mousterian in American Heritage Dictionary 4
(mo͞o-stîrˈē-ən)
adjective
Designating or belonging to a Middle Paleolithic culture following the Acheulian, associated with Neanderthals and characterized by the use of flake tools.