immaturity

Etymology

It is borrowed from Latin immātūritās (“prematureness, untimeliness; unripeness”),^[2][3][4] from immātūrus (“unripe, untimely”), with the suffix -tās;^[2][3] the adjective is formed from in- (“not”) and mātūrus (“ripe, timely”), the source of mature.^[3] The Shorter Oxford and Dictionary.com derive it instead from immature and -ity, the latter probably reflecting the Latin noun.^[5][6] The OED compares immaturité in Middle French (16th century) and Italian immaturità (1598).^[2]

Earliest recorded meaning

Prematureness, untimeliness: about 1550, in a translation of Polydore Vergil's English History.^[2] Etymonline dates it to the 1530s,^[3] Dictionary.com to 1530–40^[6] and Merriam-Webster Unabridged to about 1550.^[4]

Semantic evolution

The first sense, untimeliness, was obsolete by the early 19th century (last record 1814).^[2] From 1593, in Gabriel Harvey, the word meant the state of being not yet fully grown or developed, unripeness;^[2] Etymonline dates the meaning "lack of maturity" to about 1600.^[3] Johnson (1755) defined it as "unripeness; incompleteness; a state short of completion".^[7] From 1651 it could also name an immature thing or act, usually in the plural.^[2][5] From 1895 it also meant behaviour or attitudes unbecoming a mature person, childishness.^[2]

Timeline

• c. 1550 – prematureness, untimeliness (obsolete by 1814).^[2]
• 1593 – the state of being not yet fully grown or developed; unripeness.^[2] Etymonline dates this meaning to about 1600.^[3]
• 1651 – an immature thing or action, usually in the plural.^[2]
• 1895 – childish behaviour or attitudes.^[2]

Meanings

Noun

1. The state or quality of being immature; lack of full growth or development: the immaturity of the young vines.^[4][2]
2. Behaviour or attitudes unsuited to an adult; childishness: His immaturity showed whenever he lost a game.^[2][4]
3. Something immature, such as a childish act; usually in the plural.^[4][2][5]
4. (obsolete, c. 1550–1814) Prematureness, untimeliness.^[2][5]

Related words

• immature
• mature
• maturity
• 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 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 Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.