Talk about English fleece (5)
I believe the answer is:
cheat
'fleece' is the definition.
(fleece can mean to cheat someone)
'talk about english' is the wordplay.
'talk' becomes 'chat' (I've seen this in another clue).
'about' indicates putting letters inside.
'english' becomes 'e' (abbreviation).
'chat' enclosing 'e' is 'CHEAT'.
(Other definitions for cheat that I've seen before include "One dealing dishonestly" , "Dishonest dealer" , "Act unfairly (in game)" , "Play dishonestly" , "Trick or swindle" .)