immature

Etymology

It is borrowed from Latin immātūrus (“unripe; untimely, premature”),^[2][3][4][5] formed from in- (“not”) and mātūrus (“ripe, timely”), the source of mature.^[3][6][7][8] Barnhart considers a back-formation from immaturity, recorded from about 1540, possible but less likely.^[4] The OED compares French immature (before 1509), Spanish inmaduro (1498), Portuguese imaturo and Italian immaturo.^[2]

Earliest recorded meaning

Untimely or premature, usually of death: 1548, in Hall's chronicle.^[2][4][3][8]

Semantic evolution

In the 16th century the word was mostly used of an early death,^[3][4] a sense the OED calls now somewhat rare and the Shorter Oxford obsolete after the mid 19th century.^[2][9] It was soon used of a stage of life before adulthood (1563) and of unripe fruit (1599).^[2][4] The main modern sense, not yet fully grown or developed, is recorded from 1610 in the OED, while Barnhart and Etymonline date it to the 1640s;^[2][4][3] it was also used of plans and ideas not yet perfected (1635).^[2] Johnson (1755) defined it as "not ripe" and "not perfect; not arrived at fulness or completion".^[10] The sense of childish behaviour, showing less emotional or intellectual development than expected, is recorded from 1902 in the OED, but from 1920 in Etymonline.^[2][3] Technical uses followed in medicine (an immature cataract, 1746) and soil science (1921), and the noun, an immature animal or bird, from 1866.^[2][5]

Timeline

• 1548 – untimely, premature, of death.^[2][4][5]
• 1563 – belonging to the stage of life before adulthood.^[2]
• 1599 – of fruit: unripe.^[2][4]
• 1610 – not fully grown or developed.^[2]
• 1635 – of a thing: not fully formed or perfected.^[2]
• 1641 – not full-grown, in Barnhart.^[4]
• 1746 – of a cataract: not yet complete.^[2]
• 1866 – noun, an immature animal or bird.^[2][5]
• 1902 – childish, lacking emotional maturity.^[2]
• 1921 – of a soil: without a fully developed profile.^[2]

Meanings

Adjective

1. Not fully grown or developed: immature salmon.^[11][5][2]
2. Lacking the emotional or intellectual development expected of an adult; childish: It was immature of him to sulk.^[11][2]
3. Of fruit: unripe.^[5][2]
4. Having the capacity to reach a full form but not yet having done so: an immature talent.^[5][2]
5. Of a soil: not having a fully developed profile.^[5][2]
6. (archaic) Premature, untimely, especially of death.^[5][2][9]

Noun

1. An immature individual, especially a bird that has lost its juvenile plumage but not yet gained its full adult plumage.^[5][2]

Word family

• immaturely
• immaturity
• immatureness

Related words

• mature
• premature

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g h i Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c d e f g h i j Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
9. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
10. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
11. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins