Some flirt with a fool (4)
I believe the answer is:
twit
'fool' is the definition.
(thesaurus)
'some flirt with a' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'TWIT' is hidden within 'flirt with a'.
(Other definitions for twit that I've seen before include "Ninny" , "Stupid person" , "Nincompoop" , "Blockhead" , "Silly fool" .)