WordNet sense 1 (a person who belongs to an early stage of civilization):

primitive person

WordNet sense 2 (of or created by one without formal training; simple or naive in style):

naive

WordNet sense 3 (not disciplined or conditioned or made adept by training):

untrained

WordNet sense 4 (belonging to an early stage of technical development; characterized by simplicity and (often) crudeness):

crude, rude

WordNet sense 5 (little evolved from or characteristic of an earlier ancestral type):

archaic

WordNet sense 6 (being or occurring at an early stage of development):

early

WordNet sense 7 (not having a high state of culture and social development):

noncivilised, noncivilized