Light ale three drunk (8)
I believe the answer is:
ethereal
'light' is the definition.
(thesaurus)
'ale three drunk' is the wordplay.
'drunk' indicates an anagram.
'ale'+'three'='alethree'
'alethree' with letters rearranged gives 'ETHEREAL'.
(Other definitions for ethereal that I've seen before include "Of the spirit" , "Take ale there: it's light and delicate" , "Spiritual" , "Airy; heavenly" , "Sublime" .)