Playwright, to a greater extent, penning fiction (7)
I believe the answer is:
moliere
'playwright' is the definition.
(Moliere is an example)
'to a greater extent penning fiction' is the wordplay.
'to a greater extent' becomes 'more' ('more' can be a synonym of 'to a greater extent').
'penning' means one lot of letters goes inside another.
'fiction' becomes 'lie' (I've seen this before).
'more' placed around 'lie' is 'MOLIERE'.
(Other definitions for moliere that I've seen before include "French dramatist" , "French playwright (Tartuffe)" , "17th century French playwright" , "Fr. dramatist (Tartuffe)" , "Fr. comic dramatist" .)