Enjoyment or vigour (5)
I believe the answer is:
gusto
I believe this is a double definition.
'enjoyment' is the first definition.
(I know that gusto is a type of enjoyment)
'vigour' is the second definition.
(I've seen this before)
(Other definitions for gusto that I've seen before include "exhilaration" , "Energy" , "Spirit" , "Hearty enjoyment" , "Zest, zeal" .)