Generous lager poured out (5)
I believe the answer is:
large
'generous' is the definition.
(similar in meaning)
'lager poured out' is the wordplay.
'poured out' indicates an anagram (I've seen this in other clues).
'lager' anagrammed gives 'LARGE'.
(Other definitions for large that I've seen before include "Big, almost regal" , "broad" , "Immense" , "Of considerable size or extent" , "Of great size" .)