un·​less | \ ən-ˈles How to pronounce unless (audio) , ˈən-ˌles\

Definition of unless

 (Entry 1 of 2)

1 : except on the condition that : under any other circumstance than
2 : without the accompanying circumstance or condition that : but that : but



Definition of unless (Entry 2 of 2)

: except possibly : except

Examples of unless in a Sentence

Recent Examples on the Web: Preposition

The Tenure of Office Act, passed in 1867, prohibited the president from firing an official appointed during his term unless the Senate approved the move. Michael Kazin, The New Republic, "The Impossibility of Impeachment," 10 June 2019 The Trump administration is threatening to slap tariffs on imports from Mexico, starting with a 5% tariff beginning on Monday and escalating to 25% by October, unless Mexico stems the flow of migrants reaching the U.S. southern border. Aimee Picchi, CBS News, "Why your tax cut is now almost entirely wiped out by tariffs," 7 June 2019 In a series of tweets and remarks over the past week, Mr. Trump vowed to impose a series of escalating tariffs on Mexican imports unless Mexico could end the surge of migrants, especially those from Central America, pressing to cross the border. Michael D. Shear, New York Times, "Mexico and the U.S. Have Made Progress Toward Averting Tariffs," 6 June 2019 Alabama state legislators last month passed a bill barring abortions at any point of a pregnancy unless the woman’s health is in danger. Howard Koplowitz | Hkoplowitz@al.com, al.com, "Pussy Riot to hold Birmingham benefit concert in response to abortion ban," 5 June 2019 Here are some cool things that won’t happen unless Lovullo steps in to change the game: Sluggers going 40-40. Greg Moore, azcentral, "As Diamondbacks slip, Torey Lovullo should lead the charge against shifts, analytics," 5 June 2019 President Donald Trump has threatened to impose 5% tariffs on Mexico starting June 10 unless the Mexican government stops the flow of migrants coming to the U.S. border. Justin L. Mack, Indianapolis Star, "Gas prices and tariffs: Why gas dropping under $2 a gallon might cost you," 5 June 2019 Upon Cuomo’s sign-off, cat owners could face fines of up to $1,000 for putting their pets through the procedure, unless it is deemed medically necessary. Madeline Fitzgerald, Time, "New York Poised to Become the First State to Ban Cat Declawing," 5 June 2019 Those under 16 would need to take an education course ahead of fishing unless fishing with an adult. Richard Tribou, orlandosentinel.com, "Florida man reels in 10-foot tiger shark, and followed the rules ... for now," 4 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'unless.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of unless


15th century, in the meaning defined at sense 1


circa 1532, in the meaning defined above

History and Etymology for unless


Middle English unlesse, alteration of onlesse, from on + lesse less

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Time Traveler for unless

The first known use of unless was in the 15th century

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English Language Learners Definition of unless

used to say what will happen, be done, or be true if something else does not happen, is not done, or is not true


un·​less | \ ən-ˈles How to pronounce unless (audio) \

Kids Definition of unless

: except on the condition that You can't have dessert unless you finish your dinner.

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Rhyming Dictionary: Words that rhyme with unless

Spanish Central: Translation of unless

Nglish: Translation of unless for Spanish Speakers

Britannica English: Translation of unless for Arabic Speakers

Comments on unless

What made you want to look up unless? Please tell us where you read or heard it (including the quote, if possible).


showing courage and determination

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