Go in hope, presumably (3)
I believe the answer is:
pep
'go' is the definition.
(I've seen this in another clue)
'in hope presumably' is the wordplay.
'in' indicates a hidden word.
'PEP' is hidden in the letters of 'hope presumably'.
(Other definitions for pep that I've seen before include "Energy or enthusiasm" , "Energy, zip" , "Palindromic energy or vim" , "Energy, liveliness" , "Palindromic vim and vigour" .)