defect

Etymology

The noun is borrowed from Latin dēfectus (“failure, absence, deficiency, shortcoming”),^[2][3][4] the noun use of the past participle of dēficiō (“to fail, desert, be wanting, revolt”),^[5][2][6] from dē- (“down, away”) and faciō (“to make, do”),^[5][3][4] from Proto-Indo-European *dhē- (“to set, put”).^[5][3] Barnhart, Etymonline and the Shorter Oxford add that it came partly through Middle French defect (“deficiency”),^[6][5][7] and Merriam-Webster gives a Middle English form defaicte;^[8] the OED's revised entry (2016) derives it from Latin only, comparing the earlier default.^[2] The verb is from dēfectus too, the past participle of the same verb;^[8][5][2] the OED notes that in post-classical Latin the noun also meant moral deficiency (5th century) and default (13th century).^[2] An adjective defect, defective, came from the same Latin participle in the late 14th century, and in later use probably also from German defekt.^[2] Klein compares deficit.^[9]

Earliest recorded meaning

The adjective, disfigured, is recorded first, before 1398 in Trevisa's translation of Bartholomaeus Anglicus.^[2] The noun is first a lack of something necessary, a deficiency: before 1425 (?), in a translation of Guy de Chauliac's Grande Chirurgie,^[2] probably before 1425 in Barnhart.^[6]

Semantic evolution

The noun at first meant a lack or want; from about 1450 it also meant an imperfection or flaw in a person or thing,^[2][6][5] the main sense today.^[8][10] Johnson (1755) gave "want; absence of something necessary" as its first sense.^[11] The noun had also briefly meant a defection (1540 to 1798) and an eclipse (1571 to 1804).^[2] Later technical senses are a naval list of repairs needed (1747) and an irregularity in a crystal lattice (1936).^[2] The verb, from the Latin participle, first meant to hurt or damage (1542), then to fall short (1587 to 1652);^[2][5] since 1596 it has meant to desert a cause or party for another,^[2][5] the sense that survives.^[8] In the Cold War it came to mean leaving a communist country for a Western one, or the reverse (1950).^[2]

Timeline

• before 1398 – adjective, disfigured.^[2]
• before 1425 – noun, a lack or deficiency.^[2][6]
• c. 1450 – an imperfection or flaw.^[2][6]
• 1542 – verb, to hurt or damage.^[2]
• 1587 – verb, to fail or fall short (obsolete by 1652).^[2][8]
• 1596 – verb, to desert a person, party or cause.^[2]
• 1936 – an irregularity in a crystal lattice.^[2]
• 1950 – to leave a communist country for a non-communist one, or the reverse.^[2]

Meanings

Noun

1. An imperfection or flaw that spoils something or makes it fail: a defect in the wiring.^[8][10][2]
2. A shortcoming or failing in a person: a defect of character.^[8][10]
3. A lack of something needed for completeness; a deficiency.^[10][2]
4. (crystallography) A local irregularity in a crystal lattice.^[10][2]

Verb

1. To desert one's country, party or cause, especially for an opposing one: Two officers defected to the other side.^[8][10][2]
2. (obsolete, 1587–1652) To fail or fall short.^[8][2]

Word family

• defection
• defector
• defectible
• defectibility
• defectless
• nondefecting
• indefectible
• redefect

Related words

• defective
• defeat
• deficiency
• deficient
• deficit
• fact
• default

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 z 27 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
5. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
10. ^ a b c d e f Collins English Dictionary (2023), Glasgow: HarperCollins
11. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.