impossible

adjective

im·​pos·​si·​ble (ˌ)im-ˈpä-sə-bəl 

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

• unlikely
• hopeless
• problematic
• impractical
• futile

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

What any of that means for Mozeliak — and by extension, Suzuki — is impossible to know. — Ken Rosenthal, New York Times, 11 Sep. 2026

But testing it has been impossible because nobody has managed to build an interferometer that could perform the necessary measurement. — Jacek Krywko, ArsTechnica, 11 Sep. 2026

And many fiscal conservatives in his own party would almost certainly stand in the way of Congress reshuffling more than $1 trillion, as the national debt reaches historic highs (new spending would be a virtually impossible sell). — Zachary Schermele, USA Today, 10 Sep. 2026

That's almost impossible to do as an NFL quarterback — especially one who fans argued should've beaten out Matt Stafford for MVP last season. — Zach Dean Outkick, FOXNews.com, 10 Sep. 2026

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

Phrases Containing impossible

• the impossible

Rhymes for impossible

• possible

Kids Definition

impossible

adjective

im·​pos·​si·​ble (ˈ)im-ˈpäs-ə-bəl 

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