The foolish snipe at the wise (7)
I believe the answer is:
sapient
'the wise' is the definition.
(thesaurus)
'the foolish snipe at' is the wordplay.
'the foolish' indicates anagramming the letters.
'snipe'+'at'='snipeat'
'snipeat' is an anagram of 'SAPIENT'.
(Other definitions for sapient that I've seen before include "Canny" , "Snipe at (anag.)" , "Literary word for wise" , "Panties (anag)" , "Discerning" .)