1 : not capable of being grasped by the mind. 2 : being contrary to what is reasonable, desirable, or probable : being out of the question. Other Words from unthinkable Synonyms & Antonyms Example Sentences Learn More About unthinkable.

What is the base word for Unthinkable?

unthinkable (adj.)

early 15c., "too large to be conceived, unimaginable," from un- (1) "not" + think (v.) + -able.

What is a unspeakable?

1a : incapable of being expressed in words : unutterable. b : inexpressibly bad : horrendous unspeakable living conditions unspeakable evil. 2 : that may not or cannot be spoken the bawdy thoughts that come into one's head—the unspeakable words— L. P. Smith unspeakable collections of consonants— Rosemary Jellis.