European cutting socialist's grass (4)
I believe the answer is:
reed
'grass' is the definition.
(I've seen this before)
'european cutting socialist's' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'cutting' indicates putting letters inside (some letters cut their way into a word).
'socialist' becomes 'red' (socialism is often associated with the colour red).
'e' placed within 'red' is 'REED'.
(Other definitions for reed that I've seen before include "One of two in a 25 [OBOE]" , "Tall grass that grows in swamps" , "Plant of marshy land" , "Marsh plant with tall straight stem" , "ancient arrow" .)