Somewhat Phoenixlike this old leader, were he to rise? (5)
I believe the answer is:
lenin
'somewhat phoenixlike this old leader were he to rise?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is the entire clue.
(Other definitions for lenin that I've seen before include "Linen for Communist" , "Revolutionary leader" , "First premier of the Soviet Union, d. 1924" , "Head of the Communist state after the fall of the Tsar" , "Soviet Union's first premier" .)