Immature synonyms such as childish, crude, babyish, and callow. Immature is an adjective, and its antonyms are ripe and mature. Additionally, here are 29 synonyms, related words, and verbs for immature.
crude, green, imperfect, incomplete, not mature, not matured, not ripe, raw, undeveloped, unfinished, unformed, unmellowed, and unripe.