Stole line written by playwright (5)
I believe the answer is:
shawl
'stole' is the definition.
(I've seen this before)
'line written by playwright' is the wordplay.
'line' becomes 'l'.
'written by' means one lot of letters go next to another.
'playwright' becomes 'shaw' (Shaw is an example).
'l' put after 'shaw' is 'SHAWL'.
(Other definitions for shawl that I've seen before include "Wrap for a baby" , "Covering for baby" , "Cape" , "It covers the head and shoulders" , "Fabric wrap" .)