deduct

Etymology

It is inherited from Middle English deducten,^[2][3] borrowed from Latin dēductus (“led down, led away”), the past participle of dēdūcō (“to lead down, bring away, derive”);^{[4][5][6][7][8]} the Middle English Dictionary also points to Old French deduit, the past participle of deduire.^[2] The Latin verb is formed from dē- (“down, away”) and dūcō (“to lead”),^[7][8] from Proto-Indo-European *deuk- (“to lead”).^[4] It is thus a doublet of deduce, from the same Latin verb.^[5][4][7]

Earliest recorded meaning

To subtract one amount from another: 1419, in the Proceedings of the Privy Council, "We shuld abate and deduct of owre forseid stok the forseid somme".^[2][5] The OED's first quotation for the verb is from 1524, but it records the participle deduct, deducted, from 1439.^[7]

Semantic evolution

From the 16th century deduct and deduce shared nearly all their senses, and in the 1600s deduct was gradually restricted to subtraction, a sense deduce has since lost;^[5] the Oxford Dictionary of English dates the separation of the two to the mid-17th century.^[9] The OED records deduct for leading out a colony (1549–1627), for drawing off a stream (1621–26), for tracing a descent (1530–1660) and for inferring by reasoning (c. 1551–1889).^[7] Until deducted replaced it, deduct itself served as the past participle (1439–1533).^[7] Johnson (1755) gave the senses "to subtract; to take away" and "to separate; to divide", the second "now not in use".^[10] Etymonline, quoting the Century Dictionary, distinguishes deduct, used of taking away portions or amounts, from subtract, used of numbers.^[4]

Timeline

• 1419 – to subtract one amount from another.^[2][5] The OED's first quotation for this sense is from 1524.^[7]
• 1439 – deduct as past participle, deducted (until 1533).^[7]
• 1530 – to derive, to trace the descent of (obsolete by 1660).^[7]
• 1549 – to lead forth a colony (obsolete by 1627).^[7]
• c. 1551 – to infer by reasoning, deduce (obsolete).^[7]
• 1621 – to draw a stream aside from the main stream (rare, obsolete).^[7]

Meanings

Verb

1. To take an amount away from a total; to subtract: The fee is deducted from your refund.^[11][6][7]
2. (intransitive, with from) To lessen or detract from: The cracked tiles deduct from the value of the house.^[6][12]
3. To deduce or infer; the OED records this sense until 1889.^[6][7]
4. (obsolete, 1530–1660) To derive; to trace the descent of.^[7][13]

Noun

1. An amount deducted; a deduction (informal).^[6]

Word family

• deductible
• deductive
• prededuct
• undeducted

Related words

• deduce
• deduction
• duct
• conduct

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d 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. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
6. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
8. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., 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. ^ Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ Gove, Philip Babcock, ed. (1961), Webster's Third New International Dictionary of the English Language, Unabridged, Springfield, Mass.: G. & C. Merriam
13. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press