indefinable vs unutterable

indefinable and unutterable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
indefinable	No	Yes	No	No
unutterable	No	Yes	No	No

As adjectives, indefinable and unutterable are synonyms defined as:

Other synonyms of indefinable include indescribable, ineffable, unspeakable, untellable.

indefinable (adjective)	unutterable (adjective)
defying expression or description	defying expression or description
not capable of being precisely or readily described; not easily put into words	too sacred to be uttered
	very difficult to pronounce correctly