Vitality, zip (4)
I believe the answer is:
zing
I believe this is a double definition.
'vitality' is the first definition.
(I've seen this in another clue)
'zip' is the second definition.
(thesaurus)
(Other definitions for zing that I've seen before include "spirit" , "Get-up-and-go" , "Go" , "Vigour" , "Energy - high-pitched buzz" .)