As nouns the difference between undefinable and indefinable
is that undefinable is anything that cannot be defined while indefinable is anything that cannot be defined.
Is there a word undefinable?
“Undefinable.” Merriam-Webster.com Dictionary, Merriam-Webster, Accessed 24 Oct. 2021.
What does the word indefinable mean?
: incapable of being precisely described or analyzed indefinable feelings an indefinable concept.