Grey ale drunk with enthusiasm (7)
I believe the answer is:
Here is my best explanation:
'with enthusiasm' is the definition.
(I've seen this before)
'grey ale drunk' is the subsidiary indication.
'drunk' is an anagram indicator.
'greyale' with letters rearranged gives 'eagerly'.
(Other definitions for eagerly that I've seen before include "Ardently and avidly", "Keenly", "In a keen manner", "Enthusiastically", "Fervently", "Avidly", "With keen anticipation" and "With enthusiasm".)