Why ease off moonshine? (7)
I believe the answer is:
eyewash
'moonshine?' is the definition.
(thesaurus)
'why ease off' is the wordplay.
'off' indicates anagramming the letters.
'why'+'ease'='whyease'
'whyease' anagrammed gives 'EYEWASH'.
(Other definitions for eyewash that I've seen before include "Bunk" , "Optic lotion - nonsense!" , "Nonsense (colloq.)" , "Insincere talk or optical lotion" , "rot?" .)