intangible

Incapable of being perceived by the senses especially the sense of touch.

“the intangible constituent of energy”

Lacking substance or reality; incapable of being touched or seen.

“that intangible thing--the soul”

Hard to pin down or identify.

“an intangible feeling of impending disaster”

(of especially business assets) not having physical substance or intrinsic productive value.

“intangible assets such as good will”

Assets that are saleable though not material or physical.