Exhales wistfully (5)
I believe the answer is:
sighs
'exhales wistfully' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sighs that I've seen before include "Bridge of - - (Venice)" , "Yearns" , "Lamentations" , "Moans" , "Exhales sadly" .)