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

Without it, dozens, including Fortich, said teaching in Miami-Dade would be impossible. — Max Klaver, Miami Herald, 4 Nov. 2026

Democrats who once saw the political map as an almost impossible lift now are now hopeful that a Senate majority is within reach, even though their path runs through several more conservative states. — Jill Colvin, Chicago Tribune, 4 Nov. 2026

Plenty of signs were there during early voting – especially in North Carolina, a killing field where Republicans lost House and state legislative seats that were gerrymandered to be impossible to lose. — David Weigel, semafor.com, 4 Nov. 2026

Video, images and other information can be transmitted to emergency managers in near real time, giving responders a broader picture of conditions in areas that may be difficult or impossible to reach by road. — Brian Maass, CBS News, 3 Nov. 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