Vague sense (4)
I believe the answer is:
vibe
'vague sense' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for vibe that I've seen before include "Atmosphere, aura" , "Perceptible aura" , "Aura experienced instinctively" , "in the air" , "Atmosphere, feeling" .)