Bit of leg shown by half-cut fems with revolutionary spirit (5)
I believe the answer is:
femur
'bit of leg' is the definition.
(the femur is a bone of the leg)
'half-cut fems with revolutionary spirit' is the wordplay.
'half cut' indicates taking half.
'with' says to put letters next to each other.
'revolutionary' says the letters should be written in reverse (letters revolve around).
'spirit' becomes 'rum' (alcoholic spirit).
'rum' back-to-front is 'mur'.
'fems' with half the letters taken is 'fe'.
'fe'+'mur'='FEMUR'
'shown by' is the link.
(Other definitions for femur that I've seen before include "Thighbone" , "bit of leg" , "Part of leg" , "Bone in leg" , "Longest bone in the human body" .)