Give up the ales or rum? (4,5)
I believe the answer is:
lose heart
'give up' is the definition.
(thesaurus)
'the ales or rum?' is the wordplay.
'rum?' indicates anagramming the letters (rum can mean strange or unusual).
'the'+'ales'+'or'='thealesor'
'thealesor' anagrammed gives 'LOSE HEART'.
(Other definitions for lose heart that I've seen before include "Become despondent" , "Become discouraged in cardiac manner?" , "Start to despair" , "Mislay a card" , "Falter in courage - or fall in love? (4, 5)" .)