Cover done within square edges (5)
I believe the answer is:
shade
'cover' is the definition.
(thesaurus)
'done within square edges' is the wordplay.
'done' becomes 'had' ('do' and 'have' can both mean to defraud).
'within' is an insertion indicator.
'edges' suggests removing the centre (I've seen 'edging' mean this (edging means the letters on the edges)).
'square' with its centre removed is 'se'.
'had' inserted within 'se' is 'SHADE'.
(Other definitions for shade that I've seen before include "remains" , "Space sheltered from the sun" , "Degree of colour" , "Area sheltered from the sun" , "Colour; lamp cover" .)