[Gasp!] (4)
'gasp' is the definition.
(I know that gasp can be written as pant)
This is the entire clue.
(Other definitions for pant that I've seen before include "Breath noisily from exertion" , "Breath rapidly" , "Breathe noisily after running" , "Gasp for breath (like a hot dog?)" , "Struggle for breath" .)