Lager better in a cocktail? It's too bad (11)
I believe the answer is:
regrettable
'it's too bad' is the definition.
(synonyms)
'lager better in a cocktail?' is the wordplay.
'in a cocktail?' indicates anagramming the letters (the letters in a mixture).
'lager'+'better'='lagerbetter'
'lagerbetter' is an anagram of 'REGRETTABLE'.
(Other definitions for regrettable that I've seen before include "Undesirable" , "ill-advised" , "Unfortunate" .)