One who stirred up revolution in large square to the west (5)
I believe the answer is:
lenin
'one who stirred up revolution' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'large square to the west' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'square' becomes 'nine' (nine is a square number).
'to the west' says the letters should be written in reverse (letters written right to left or 'east to west').
'nine' in reverse letter order is 'enin'.
'l'+'enin'='LENIN'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for lenin that I've seen before include "Marxist theoretician" , "First premier of the Soviet Union, d. 1924" , "Head of the Communist state after the fall of the Tsar" , "Vladimir Ilyich Ulyanov, d. 1924" , "Revolutionary man" .)