Positive response a company sent back for playwright (6)
I believe the answer is:
ocasey
'for playwright' is the definition.
(Sen O'Casey, 1880-1964)
'positive response a company sent back' is the wordplay.
'positive response' becomes 'yes' (positive response to a question).
'company' becomes 'co' (abbreviation).
'sent back' shows that the letters should be reversed in order.
'yes'+'a'+'co'='yesaco'
'yesaco' back-to-front is 'OCASEY'.
(Other definitions for ocasey that I've seen before include "Sean ..., author of 'The Plough and the Stars'" , "Sean . . . . . . wrote 'Juno and the Paycock'" , "Sean . . . . . . wrote ''The Plough and the Stars'' (1 '5)" , "Sean .'..... wrote ` `The Shadow of a Gunman' ' (1'5)" , "Sean . . . . . ., great Irish playwright of 'The Plough and the Stars' (1'5)" .)