[adj] indicating a lack of maturity; "childish tantrums"; "infantile behavior" [adj] being or befitting or characteristic of an infant; "baby rabbits" [adj] of or relating to infants or infancy; "infantile paralysis"
baby(a), childish, immature, infant(a), young
abecedarian, aboriginal, antenatal, autochthonous, babish, baby, babyish, beginning, budding, childish, childlike, creative, dollish, doll-like, elemental, elementary, embryonic, fetal, formative, foundational, fundamental, gestatory, immature, in arms, i