unspeakable vs indefinable

unspeakable and indefinable both are adjectives.

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

As adjectives, unspeakable and indefinable are synonyms defined as:

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

unspeakable (adjective)	indefinable (adjective)
exceptionally bad or displeasing	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