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

That’s the kind of streak that should be impossible. —Dan Santaromita, New York Times, 25 Apr. 2026

So local schools and other governmental units presumably would have to ask for twice as much money to get the same amount, which might make such a deal financially impossible. —Robert McCoppin, Chicago Tribune, 24 Apr. 2026

Nearly half of Americans feel homeownership is impossible Amazon Prime is offering a 20-cent-per-gallon discount. —Gili Malinsky, CNBC, 24 Apr. 2026

In the long term, California will continue to be extremely vulnerable to geopolitical events around the world unless new inbound pipeline capacity is created (not expected until at least 2029) or increased in-state crude production is increased (which Sacramento has made virtually impossible). —James Rector, San Diego Union-Tribune, 24 Apr. 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