impossible

adjective

im·​pos·​si·​ble (ˌ)im-ˈpä-sə-bəl How to pronounce impossible (audio)
Synonyms of impossible
1
a
: incapable of being or of occurring
It's impossible to tell the future.
b
: felt to be incapable of being done, attained, or fulfilled : insuperably difficult
an impossible deadline
2
a
: extremely undesirable : unacceptable
in an impossible situation
b
: extremely awkward or difficult to deal with
The actor was impossible on the set.
impossibleness noun

Synonyms of impossible

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Examples of impossible in a Sentence

It's impossible to predict the future. The heavy rain made it impossible to see the road. It's physically impossible for a child to lift that much at once. It's virtually impossible to book a flight just before the holiday. These math problems are impossible! You refuse to help and then criticize me for not doing it right? You're impossible! My boss is just an impossible woman.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
However, if agreement proves impossible and an impasse is declared, a three-member arbitration panel would take over. — Jon Regardie, Los Angeles Times, 27 Oct. 2026 For an industry that’s already forced to navigate competing union interests, corporate headwinds, and endless miles of red tape, adding another layer of compliance may seem impossible. — Hillary Busis, Vanity Fair, 27 Oct. 2026 Marylanders, and Americans generally, deserve to see the full picture before the compounding numbers become impossible to ignore. — Judi Willard, Baltimore Sun, 27 Oct. 2026 For truck driver and coordinator Matthew Benigar, the rising costs are impossible to ignore. — Kelly Werthmann, CBS News, 27 Oct. 2026 See All Example Sentences for impossible

Word History

Etymology

Middle English, from Anglo-French & Latin; Anglo-French, from Latin impossibilis, from in- + possibilis possible

First Known Use

14th century, in the meaning defined at sense 1a

Time Traveler
The first known use of impossible was in the 14th century

Phrases Containing impossible

Rhymes for impossible

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Browse Nearby Words

impossibility
impossible
impossibly
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Cite this Entry

“Impossible.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/impossible. Accessed 29 Oct. 2026.

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Kids Definition

impossible

adjective
im·​pos·​si·​ble (ˈ)im-ˈpäs-ə-bəl How to pronounce impossible (audio)
1
a
: incapable of being or of occurring
b
: very difficult : hopeless
an impossible situation
2
: very bad or unpleasant
an impossible person
impossibly
-blē
adverb

Legal Definition

impossible

adjective
im·​pos·​si·​ble
: not possible : incapable of being done, attained, or fulfilled
a party's performance is impossible in part
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