impossible

adjective

im·​pos·​si·​ble (ˌ)im-ˈpä-sə-bəl 

1

a

: incapable of being or of occurring

b

: felt to be incapable of being done, attained, or fulfilled : insuperably difficult

an impossible deadline

2

a

: extremely undesirable : unacceptable

b

: extremely awkward or difficult to deal with

the actor was impossible on the set

impossibleness noun

Synonyms

• unlikely
• hopeless
• problematical
• 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

Rather interestingly, instead of making off with the loot, the hackers sent the proceeds to addresses with no owners, effectively destroying the value and making recovery impossible, in order to emphasise the political, rather than financial, nature of the raid. —David G.w. Birch, Forbes.com, 25 Aug. 2025

The hedge is an acceptance that the world is impossible to know accurately. —Zach Helfand, New Yorker, 25 Aug. 2025

The striking shift in tone — from enmity to friendliness — is impossible to ignore. —Hanako Montgomery, CNN Money, 24 Aug. 2025

Though shutting down Thomas is impossible – after all, Thomas put up a triple double – Rupert still had her moments against the MVP candidate. —Joseph Dycus, Mercury News, 23 Aug. 2025

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