im·ma·ture 
/ɪməˈtuɚ, ɪməˈtʃɚ/ adjective
/ɪməˈtuɚ, ɪməˈtʃɚ/ adjective : not mature: such as a : not fully developed or grown
▪ The flock included both adult and immature birds. ▪ The fruit was still immature. [=unripe]
b [more immature; most immature] : acting in a childish way : having or showing a lack of emotional maturity
▪ emotionally immature adults ▪ His teachers have complained about his immature behavior.
▪ The flock included both adult and immature birds. ▪ The fruit was still immature. [=unripe]
b [more immature; most immature] : acting in a childish way : having or showing a lack of emotional maturity
▪ emotionally immature adults ▪ His teachers have complained about his immature behavior.
— im·ma·tu·ri·ty /ɪməˈturəti, ɪməˈtʃɚrəti/ noun [noncount]
▪ His tantrums are a sign of immaturity.
/ɪməˈturəti, ɪməˈtʃɚrəti/ noun [noncount] ▪ His tantrums are a sign of immaturity.
