Considered some communist, leftie revolutionary (4)
I believe the answer is:
felt
'considered' is the definition.
(feel can mean to consider or think)
'some communist leftie revolutionary' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'revolutionary' shows that the letters should be reversed in order.
'tlef' is hidden in the letters of 'communist leftie'.
'tlef' reversed gives 'FELT'.
(Other definitions for felt that I've seen before include "Ran one's hand over" , "Cloth of pressed wool and fur" , "Sensed - beret material" , "hat-maker" , "Considered" .)