Go in hope, perhaps (3)
I believe the answer is:
pep
'go' is the definition.
(both can mean energy or vitality)
'in hope perhaps' is the wordplay.
'in' indicates the answer is hidden within the clue.
'PEP' is hidden within 'hope perhaps'.
(Other definitions for pep that I've seen before include "Ginger; tax-free investment" , "Energy, zip" , "Palindrome for vitality or energy" , "Palindromic vim and vigour" , "Palindrome for vigour" .)