unthinkable

Adjective

• incapable of being conceived or considered

Adj

• Incapable of being believed; incredible.
• Inconceivable or unimaginable; extremely improbable in a way that goes against common sense.
• Extremely improper; extremely at odds with norms of expected behavior; taboo.

Examples

• Nothing is unthinkable, nothing impossible to the balanced person, provided it comes out of the needs of life and is dedicated to life's further development - Lewis Mumford

Antonyms

thinkable