Poet's private room almost west-facing (5)
I believe the answer is:
eliot
'poet's' is the definition.
(TS Eliot)
'private room almost west-facing' is the wordplay.
'private room' becomes 'toilet' (room used in private).
'almost' means to remove the last letter (almost the whole word is kept).
'west-facing' says the letters should be written in reverse (letters written right to left or east to west).
'toilet' with its last letter taken away is 'toile'.
'toile' in reverse letter order is 'ELIOT'.
(Other definitions for eliot that I've seen before include "Four Quartets poet" , "thin material rejected" , "Pseudonymous writer" , "Author of Adam Bede, d.1880" , "George - - (novelist)" .)