Sly person with little support (6)
I believe the answer is:
weasel
'sly person' is the definition.
(I've seen this before)
'with little support' is the wordplay.
'with' becomes 'w' (abbreviation).
'little support' becomes 'easel' (easel is a kind of support. I am not sure about the 'little' bit.).
'w'+'easel'='WEASEL'
(Other definitions for weasel that I've seen before include "Stoat's relative" , "Carnivore; treacherous person (colloq.)" , "Predator" , "Stoat-like mammal - treacherous type" , "Small fierce animal with slender body and reddish-brown fur" .)