Effect of ale is ... er ... getting drunk! (7)
I believe the answer is:
realise
'effect' is the definition.
(I've seen this before)
'ale is er getting drunk' is the wordplay.
'getting drunk' is an anagram indicator.
'ale'+'is'+'er'='aleiser'
'aleiser' anagrammed gives 'REALISE'.
'of' is the link.
(Other definitions for realise that I've seen before include "work out" , "catch on" , "Ears lie (anag.)" , "produce" , "Apprehend; see lair (anag.)" .)