Synonyms of 'childish'

asinine, babyish, backward, beardless, boyish, childlike, coltish, decrepit, doddering, doited, doting, fatuous, foolish, girlish, immature, inexperienced, infantile, infantine, juvenile, maiden, moronic, naive, puerile, retarded, senile, silly, simple, slow, sophomoric, underdeveloped, unsophisticated, wanting