I left playwright during fantastic time away (7)
I believe the answer is:
absence
'time away' is the definition.
(eg absence from work)
'i left playwright during fantastic' is the wordplay.
'left' indicates named letters should be taken away.
'playwright' becomes 'ibsen' (Henrik Ibsen, 1828-1906).
'during' means one lot of letters goes inside another.
'fantastic' becomes 'ace' (ace can informally mean very good).
'ibsen' with 'i' taken out is 'bsen'.
'bsen' inserted inside 'ace' is 'ABSENCE'.
(Other definitions for absence that I've seen before include "State of being away" , "It's said to make the heart grow fonder" , "Want, lack" , "It makes the heart grow fonder, they say" , "what can be heart-warming?" .)