untrustworthy

Etymology

It is formed from English un- + trustworthy, with the negative prefix.^[2][3][4] The adjective trustworthy is recorded from 1658 in the revised OED;^[2] Etymonline dates it to 1791.^[3] The older word for the same idea was untrusty, recorded from before 1387 in Trevisa's translation of Higden's “Polychronicon”,^[2] and Middle English also had a verb and a noun untrust, distrust, from about 1200.^[3]

Earliest recorded meaning

Not worthy of trust; unreliable: 1846, in J. E. Worcester's Universal Dictionary of the English Language.^[2][3] The Shorter Oxford dates the word to the mid 19th century.^[4]

Semantic evolution

The word has kept the single sense "not to be trusted, unreliable", used of people and of things such as information or evidence.^[2][5][6] It took over from the older untrusty, which the Shorter Oxford now labels archaic.^[4][3] The noun untrustworthiness is recorded earlier than the adjective, from 1808 in J. Bentham.^[2][3]

Timeline

• 1846 – not deserving trust; unreliable.^[2][3]

Meanings

Adjective

1. Not deserving trust or confidence; unreliable or likely to deceive: The jury found the second witness untrustworthy.^[6][5][2][4]

Related words

• trust
• trustworthy
• untrusty
• distrust
• mistrust

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins