mature Antonyms

immature childish premature slip slump sophomoric stagnate subside superficial teen teenage tender unacquainted unfledged unformed unripe slide sink silly prepaid pubescent puerile pupal puppyish raw raze recidivate regress relapse retrograde retrogress revert sentimental unseasoned unsophisticated underdeveloped undeveloped kiddish fall off preadolescent prepubertal prepupal schoolgirlish unaged undigested undried untried unversed well-preserved neonatal