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

These features can only result from the intense conditions generated by an impact event, impossible under normal Earth-surface conditions. —Bojan Stojkovski, Interesting Engineering, 25 Oct. 2025

At some point, the truth becomes impossible to ignore. —Lizzie Lanuza, StyleCaster, 25 Oct. 2025

If its lawyers were unable to enter federal buildings or courthouses, representation of clients before federal courts and agencies would become impossible. —Fabio Bertoni, New Yorker, 25 Oct. 2025

Meaningful economic activity has become largely impossible. —Anna Halford, Time, 25 Oct. 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