His teachers have complained about his 'immature' behavior.
The flock included both adult and 'immature' birds.
The fruit was still 'immature'. [='unripe']
(..) - I know someone who would disagree. - Who? My Physics Bowl trophy. Leonard is so smart. - Sheldon who? - All right, that is very immature. You're right. I'm sorry. I'm not! - Okay, new contest. - What are you doing? I am settling once and for all (..)2008 TvShow: The Big Bang Theory Title: The Bat Jar Conjecture Season: 1 Episode 13