noun-modifying (irregular)
indescribable; exquisite; inexpressible
Literary expression used to describe something so beautiful, moving, or profound that it cannot be put into words. Often modifies nouns like 美しさ or 景色.
See also: えも言われぬ (えもいわれぬ)
えも言われず美しい夕焼けだった。
It was an indescribably beautiful sunset.
その絵にはえも言われず心を打たれた。
I was moved beyond words by that painting.
Same meaning and usage; えも言われぬ is the classical attributive form (連体形) and is slightly more literary, while えも言われず is the modernized version. Both are interchangeable in modern Japanese.
From え (old Japanese particle meaning 'can') + も (inclusive particle) + 言われず (negative continuative of 言う 'to say'), literally 'cannot even be said'. The exact historical derivation is uncertain, but the phrase has been used in classical Japanese to express ineffability.