improper

Etymology

Most dictionaries take it as borrowed from French impropre or directly borrowed from Latin improprius (“unsuitable, not proper”),^{[2][3][4][5][6]} formed from in- (“not”) and proprius (“one's own, particular”), the source of proper.^[6][7][8] The French word is recorded from 1372.^[9] The OED instead treats it as formed from English im- + proper on the model of the French and Latin words.^[9] Barnhart takes it from Old French impropre.^[8]

Earliest recorded meaning

Not truly belonging to the thing in question; not in accordance with fact, reason or rule, incorrect: 1531, in Elyot's Boke Named the Gouernour.^[9] Etymonline dates the adjective, in the sense "not true", to the mid-15th century,^[5] and Barnhart finds it implied before 1393 in the adverb improprelich, improperly.^[8]

Semantic evolution

The word first meant "incorrect, irregular", a sense that gave the mathematical improper fraction, one whose numerator is at least as great as its denominator, recorded from 1552 in Recorde's Ground of Artes.^[9][2] From 1570 it also meant unsuitable or ill-adapted to a purpose,^[9] and Johnson (1755) listed "not well adapted; unqualified" and "unfit" as its first senses.^[10] The sense "contrary to good manners, modesty or decency" appears in 1739, in a letter of Lord Chesterfield.^[9][5] A rare verb improper, to behave improperly, is recorded once, in Horace Walpole (1791).^[9]

Timeline

• 1531 – not in accordance with fact or rule; incorrect.^[9]
• 1552 – improper fraction.^[9]
• 1570 – unsuitable, unfit, inappropriate.^[9][5]
• 1739 – contrary to good manners or decency; unseemly.^[9][5]
• 1791 – verb, to behave improperly (rare, obsolete).^[9]

Meanings

Adjective

1. Not in keeping with accepted standards of propriety, modesty or decency; unseemly: an improper remark at the dinner table.^[11][7][9]
2. Not suited to a use or occasion; inappropriate: Using a kitchen knife as a screwdriver is an improper use of the tool.^[11][7]
3. Not in accordance with fact, rule or correct procedure; incorrect or irregular: improper payments to officials.^[7][11][9]
4. improper fraction: a fraction whose numerator is equal to or greater than its denominator.^[9][2]

Word family

• improperly
• improperness
• improper fraction
• improper integral

Related words

• proper
• property
• propriety
• impropriety
• appropriate

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
3. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
4. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
5. ^ a b c d e 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. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ a b c Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
9. ^ 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
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 c Collins English Dictionary (2023), Glasgow: HarperCollins