i-adjective
ineffable; inexpressible; beyond words
Used for feelings, beauty, or experiences that cannot be adequately put into words. Often appears as a set phrase modifying a noun or as a predicate.
その景色の美しさは言葉に表せない。
The beauty of that scenery is beyond words.
言葉に表せないほどの感
I was moved in a way that words cannot express.