dubious

Etymology

It is borrowed from Latin dubiōsus (“doubtful”),^[2][3][4][5] from dubium (“doubt”), the neuter of dubius (“wavering, doubtful”),^[2][6][4] from duo (“two”), with the sense of being undecided between two things.^[6][3][4] Etymonline calls dubiōsus Late Latin,^[6] and the American Heritage Dictionary, Merriam-Webster and Collins derive the English word from dubius itself.^[7][8][9] Klein and Barnhart reconstruct dubius as Proto-Indo-European *du-bhw-iyos (“being double, of two natures”), formed from the stem of duo and Proto-Indo-European *bheu- (“to be”);^[10][3] the root of duo is Proto-Indo-European *dwo- (“two”).^[6][7] Weekley compares German Zweifel (“doubt”), from zwei (“two”), and Old English twēo (“doubt”),^[11] and Etymonline notes that Old English used twēo for doubt.^[6] The word is related to doubt, which came through French.^[12][4]

Earliest recorded meaning

Causing doubt; uncertain, ambiguous, vague: 1548, in Hall's chronicle of the union of Lancaster and York.^[2][3]

Semantic evolution

From 1632 it was also used of the person who doubts, wavering or hesitating in opinion,^[2][6] the sense in which the Oxford Dictionary of English places its first use.^[13] From 1635 it meant of uncertain outcome,^[2] and Johnson (1755) gave both the doubting and the doubted senses.^[14] The sense "of questionable character, suspect" is recorded from 1860, in Tyndall's Glaciers of the Alps.^[2] In Leicestershire and Shropshire dialect it was pronounced dubous or jubous, meaning undecided.^[15]

Timeline

• 1548 – occasioning doubt; uncertain, ambiguous.^[2][3]
• 1632 – of a person, wavering, hesitating in opinion.^[2]
• 1635 – of uncertain outcome.^[2]
• 1860 – of questionable or suspected character.^[2]

Meanings

Adjective

1. Unsure or doubtful about something; hesitating: She was dubious about the new schedule.^[8][9][2]
2. Of questionable quality, honesty or worth; suspect: a man with a dubious past.^[9][8][2]
3. Giving rise to doubt; ambiguous or unclear.^[8][9][2]
4. Of uncertain outcome.^[2][8][9]

Word family

• dubiously
• dubiousness
• superdubious
• undubious

Related words

• doubt
• dubiety
• indubitable
• two
• dual

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
5. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins
10. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
11. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
12. ^ Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
13. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
14. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
15. ^ Wright, Joseph, ed. (1898–1905), The English Dialect Dictionary, 6 vols., Oxford: Henry Frowde; via EDD Online 4.0, University of Innsbruck (CC BY 4.0)