形容词

1. 难以形容的;无法描述的
You use indescribable to emphasize that a quality or condition is very intense or extreme, and therefore cannot be properly described.

1. defying expression or description

e.g. indefinable yearnings
indescribable beauty
ineffable ecstasy
inexpressible anguish
unspeakable happiness
unutterable contempt
a thing of untellable splendor

Synonym: indefinableineffableunspeakableuntellableunutterable