Sly person loses head, finding support (5)
I believe the answer is:
easel
'support' is the definition.
(easel is a kind of support)
'sly person loses head' is the wordplay.
'sly person' becomes 'weasel' (I've seen this before).
'loses head' means to remove the first letter.
'weasel' with its first letter removed is 'EASEL'.
'finding' acts as a link.
(Other definitions for easel that I've seen before include "art supporter" , "Supporter for the artist" , "Artist's supporting frame" , "Van Gogh's stand?" , "Artist's equipment" .)