"an indefinable feeling of terror"
"an abstract concept that seems indefinable"
"indefinable yearnings"
"indescribable beauty"
"ineffable ecstasy"
"inexpressible anguish"
"unspeakable happiness"
"unutterable contempt"
"a thing of untellable splendor"
There was that indefinable sense of spring in the air.
出自: H. Sturgis