Too great or extreme to be expressed or described in words.
Not to be uttered.
" I had forgotten all; I knew not what was passing in me; with my soul rather than my senses, I breathed an air of ineffable sweetness.
Neo Platonism seeks this in the ecstatic intuition of the ineffable One.
ineffable sweetness
ineffable intuition
Indescribable
Unutterable
Expressible
Secular
Ineffably