Spin tail of monkey in metal frame (6)
I believe the answer is:
gyrate
'spin' is the definition.
('gyrate' can be a synonym of 'spin')
'tail of monkey in metal frame' is the wordplay.
'tail of' suggests the final letters.
'in' is an insertion indicator.
'metal frame' becomes 'grate'.
The last letter of 'monkey' is 'y'.
'y' placed into 'grate' is 'GYRATE'.
(Other definitions for gyrate that I've seen before include "Twirl" , "Spin round" , "wheel" , "Spiral about a point" , "Spin at speed" .)