from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Not fully grown or developed. See Synonyms at young.
  • adj. Marked by or suggesting a lack of normal maturity: silly, immature behavior.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Not fully formed or developed, unripe.
  • adj. Silly or childish in behavior.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Not mature; unripe; not arrived at perfection of full development; crude; unfinished
  • adj. Premature; untimely; too early.

from The Century Dictionary and Cyclopedia

  • Not mature or ripe; not complete in growth or development; hence, unfinished; not perfected: as, immature fruit; an immature youth; immature plans or counsels.
  • Coming before the natural time; premature; too early.
  • Synonyms Raw, green, crude, unfinished, undigested.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. (of birds) not yet having developed feathers
  • adj. not yet mature
  • adj. (used of living things especially persons) in an early period of life or development or growth
  • adj. not fully developed or mature; not ripe
  • adj. characteristic of a lack of maturity


Latin immātūrus : in-, not; see in-1 + mātūrus, mature; see mā-1 in Indo-European roots.
(American Heritage® Dictionary of the English Language, Fourth Edition)


  • He thinks immature will be a big engine for growth. $11 billion has been invested in immature companies.

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  • 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:

    Items under the peanut recall | In Depth -

  • 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.

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  • 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!

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  • 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.

    Texas Lawmaker Proposes Guns On Campus

  • 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!

    Think Progress » Reid to unveil intel oversight legislation at YearlyKos.

  • He asked whether this was “an immature medium in immature hands.”

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  • Bachelors were characterized as immature, narcissistic, and even deviant.

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  • But it's hard to argue that we are anywhere near winning any trophies, and certainly a certain French immature youngster seems to have given up on the club already.

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  • Two that I often quote are one by the Yankee Group that noted that 60 percent of "IT influencers" now consider cloud computing services an enabler, versus 40 percent who considered it "immature"--a complete reversal from 2009.



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  • "I think if there are allegations based on questions or comments that I made in debate prep about NAFTA or about the continent versus the country when we talk about Africa there, then those were taken out of context, and that is cruel and mean-spirited, it's immature, it's unprofessional, and those guys are jerks," Palin said." (Reuters)

    "Are not!"
    "Are too!"
    "Are not!"
    "Are too. And I call dibs on ending this right now, no take backs! Jerks!"

    November 8, 2008