Playwright is keeping individual company (7)
I believe the answer is:
ionesco
'playwright' is the definition.
(I know that Ionesco is a playwright)
'is keeping individual company' is the wordplay.
'keeping' means one lot of letters goes inside another.
'individual' becomes 'one' (an individual is one person).
'company' becomes 'co' (abbreviation).
'is' going around 'one' is 'iones'.
'iones'+'co'='IONESCO'
(Other definitions for ionesco that I've seen before include "Playwright associated with the theatre of the absurd" , "Absurdist playwright" , "French dramatist, leading figure in the theatre of the absurd, d. 1994" , "O so nice (anag) - playwright" , "Eugene -, Romanian-born French playwright" .)