Short answer is in case of typecast writer (9)
I believe the answer is:
dramatist
'writer' is the definition.
(dramatist is a kind of writer)
'short answer is in case of typecast' is the wordplay.
'short' becomes 'dram' (both can mean a small alcoholic drink).
'answer' becomes 'a' (abbreviation eg in Q and A).
'in' is an insertion indicator.
'case of' suggests removing the centre (outsides of).
'typecast' with its middle taken out is 'tt'.
'is' going inside 'tt' is 'tist'.
'dram'+'a'+'tist'='DRAMATIST'
(Other definitions for dramatist that I've seen before include "Writer of plays" , "Wordsmith" , "O'Neill or O'Casey, for example" , "Playwright" , "One who writes plays" .)