Maroon a person of radical tendencies (3)
I believe the answer is:
red
'maroon' is the definition.
(I've seen this in another clue)
'a person of radical tendencies' is the wordplay.
I cannot quite understand how this works, but
'radical' could be 'r' (chemistry abbreviation) and 'r' is located in the answer.
The remaining letters 'ed' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for red that I've seen before include "Primary colour" , "Colour of garnets" , "Blushing" , "Colour of blood" , "Ruby" .)