Garment a playwright has left (5)
I believe the answer is:
shawl
'garment' is the definition.
(shawl is a kind of garment)
'a playwright has left' is the wordplay.
'a playwright' becomes 'shaw' (George Bernard Shaw).
'has' says to put letters next to each other.
'left' becomes 'l' (common abbreviation).
'shaw'+'l'='SHAWL'
(Other definitions for shawl that I've seen before include "Covering for head and shoulders" , "Woman assumes this" , "Baby wrapper" , "Loose garment for head or shoulders" , "Cloth wrapped over one's shoulders" .)