Dramatist has extra holding whopper (7)
I believe the answer is:
moliere
'dramatist' is the definition.
(Moliere is an example)
'extra holding whopper' is the wordplay.
'extra' becomes 'more' (I've seen this before).
'holding' is an insertion indicator.
'whopper' becomes 'lie' (I've seen this before).
'more' going around 'lie' is 'MOLIERE'.
'has' is the link.
(Other definitions for moliere that I've seen before include "French writer" , "Fr. comic dramatist" , "Fr. dramatist (Tartuffe)" , "French playwright (Tartuffe)" , "17th century French playwright" .)