unless

Pronunciation

• IPA: /ənˈles/^[1]

Etymology

It is inherited from Middle English unlesse,^[2][3] an alteration of earlier onlesse, originally the phrase on lesse (than), “on a less condition (than)”,^[3][4][2] a compound, from Middle English on (“on”) + lesse (“less”).^[2][5] Hoad says the phrase was modelled on French à moins que.^[6] The first syllable became un- because the word expresses negation and is unstressed, by association with the prefix un-.^[3][4][7]

Earliest recorded meaning

As a phrase, “on a less or lower condition than”: about 1400.^[8][9] Barnhart records onlesse in 1438 and unlesse in 1467,^[3] and Etymonline dates the conjunction to the mid-15th century.^[4]

Semantic evolution

In its early use the phrase was followed by than or that, uses now obsolete.^[8] As a conjunction meaning “except if, if not”, with the following conjunction left out, it is from 1509,^[8] and as a preposition, “except, but”, from 1531–32.^[8][6] The Century Dictionary noted that except could once be used as a synonym for unless, but that the two had drawn apart, unless being only a conjunction.^[4] In Shetland Scots it appears as aless, and in Roxburghshire and Dumfriesshire as onless.^[10]

Timeline

• c. 1400 – on a less condition than.^[8]
• 1438 – onlesse.^[3]
• 1467 – unlesse.^[3]
• 1509 – conjunction, if not.^[8]
• 1531–32 – preposition, except.^[8]

Modern meaning

Conjunction

1. Except on the condition that; if not: we'll go unless it rains.

Preposition

1. (rare) Except; but.

Related words

• less
• except
• lest

References

1. ^ Jones, Daniel (2011), Cambridge English Pronouncing Dictionary, 18th ed., ed. Peter Roach, Jane Setter and John Esling, Cambridge: Cambridge University Press
2. ^ a b c The American Heritage Dictionary of the English Language (2000), 4th ed., Boston: Houghton Mifflin
3. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
7. ^ Soanes, Catherine; Stevenson, Angus, eds. (2004), Concise Oxford English Dictionary, 11th ed., Oxford: Oxford University Press
8. ^ a b c d e f g Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
9. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
10. ^ 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)