A psychic may sense it (4)
I believe the answer is:
aura
'a psychic may sense it' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aura that I've seen before include "Distinctive quality around a person or place" , "Intangible quality surrounding a person or thing" , "Glorious glow" , "Distinct but intangible quality about a person" , "Intangible air or quality" .)