infantile

Etymology

It is inherited from Middle English infantil,^[2][3] borrowed from Late Latin īnfantīlis (“of an infant”),^[4][5][3][6] from īnfāns (“young child”), the source of infant.^[4][5][3][6] The Oxford Dictionary of English and the Shorter Oxford allow French infantile as a second source,^[7][8] Merriam-Webster takes the word as probably from French,^[9] and the OED notes the French adjective from the 16th century.^[4] The Latin noun is the noun use of the adjective īnfāns, unable to speak, formed from in- (“not”) and fāns, the present participle of for (“to speak”).^[4][5]

Earliest recorded meaning

Of infancy, very young: about 1443, in Pecock's Rule, in the phrase infantil age.^[2] Etymonline dates the word to the mid 15th century.^[5]

Semantic evolution

After its 15th-century use the word is next recorded in 1696, in the general sense "of or relating to an infant or infancy",^[4][10][9] and Johnson (1755) gave only that sense, illustrating it with a fly in its infantile state.^[11] The sense "like an infant", and so childish or immature, appears in 1772, in J. Priestley.^[4][5][10] From 1885 geologists applied it to a landscape at the earliest stage of the cycle of erosion.^[4][9] Medical terms such as infantile paralysis, an old name for poliomyelitis, use the first sense.^[8]

Timeline

• c. 1443 – of infancy, very young.^[2]
• 1696 – relating to infants or infancy; at the earliest stage of development.^[4][9]
• 1772 – like an infant; childish.^[4][5]
• 1885 – in geology, of a landscape at the earliest stage of erosion.^[4]

Meanings

Adjective

1. Of, relating to or typical of infants or infancy: infantile diseases.^[12][9][4]
2. Childish or immature in behaviour; puerile: His infantile sulking embarrassed the whole team.^[12][9][8]
3. In an early stage of development.^[12][4]
4. In geology, of a landscape or landform: at the earliest stage of the cycle of erosion.^[4][9]

Word family

• infantility
• infantilism
• infantile autism
• infantile paralysis

Related words

• infant
• infancy

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
5. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
8. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
10. ^ a b Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
11. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
12. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins