Too great or extreme to be expressed or described in words.

Ineffable

NicWord of the Day0 Comments

Ineffable

in·ef·fa·bul adjective

Too great, powerful, beautiful, etc., to be described or expressed.

Dictionary.com
Ineffability is concerned with ideas that cannot or should not be expressed in spoken words (or language in general), often being in the form of a taboo or incomprehensible term.
wikipedia.org
Too great or intense to be expressed in words; unutterable
thefreedictionary.com