Synonyms of impossible

impossible

adjective

(ˌ)im-ˈpä-sə-bəl 

as in unlikely

incapable of being solved or accomplished

the seemingly impossible problem of world hunger

fitting everything in my backpack seemed an impossible task

Synonyms & Similar Words

• unlikely
• hopeless
• problematic
• impractical
• futile
• unattainable
• incredible
• insoluble
• unrealizable
• useless
• absurd
• undoable
• impracticable
• insuperable
• unsolvable
• insolvable
• infeasible
• questionable
• improbable
• unfeasible
• unworkable
• dubious
• inconceivable
• unusable
• unthinkable
• ridiculous
• unbelievable
• implausible
• unimaginable
• suspicious
• doubtful
• debatable
• suspect
• shaky
• disputable
• fishy
• far-fetched
• fantastic
• outlandish
• shady
• preposterous
• doubtable

Antonyms & Near Antonyms

• possible
• feasible
• achievable
• workable
• reasonable
• useful
• attainable
• practical
• soluble
• applicable
• practicable
• doable
• likely
• functional
• probable
• usable
• working
• serviceable
• realizable
• acceptable
• resolvable
• plausible
• conceivable
• credible
• believable

Example Sentences

Recent Examples of impossible

Just three years ago, Fanny Lumsden had an on-stage moment that’s near-impossible to beat. — Lars Brandle, Billboard, 30 Oct. 2026

Large ships rely on massive generators and motors that are often difficult or impossible to remove for maintenance. — Christopher McFadden, Interesting Engineering, 30 Oct. 2026

North Koreans live under institutions designed to make independent organization impossible. — Jieun Baek, Foreign Affairs, 30 Oct. 2026

From droughts and wildfires to floods and slow, rolling nature degradation, fashion’s nature risks are becoming impossible to ignore. — Bella Webb, Vogue, 29 Oct. 2026