immature

IPA: ɪmʌtjˈʊr

(now rare) Occurring before the proper time; untimely, premature (especially of death).
Not fully formed or developed; not grown.
Childish in behavior; juvenile.

Examples of "immature" in Sentences

He thinks immature will be a big engine for growth. $11 billion has been invested in immature companies.
And nobody on here cares about your stupid put downs and name calling on TP threads just proves you are under 25 and plain immature!
As for all of you Hillary supporters who threaten to stay home or vote for McCain, again immature and mindless because your anger will hurt all of us – grow up!
As much as I like the college world, it has done a huge disservice to many people because it has allowed them to remain immature and irresponsible for longer than people of my parents 'or grandparents' generation.
The following recalls have been announced, since a products could be infested with salmonella!, an mam mal that can means critical as well as sometimes deadly infections, especially in immature children, a elderly as well as those with weakened defence systems:
Nassau Candy is recalling twenty-six peanut bulk products since they could be infested with salmonella, an mammal that can means critical as well as sometimes deadly infections, especially in immature children, a elderly as well as those with weakened defence systems.