Sly character in western given help by lawman, at first (6)
I believe the answer is:
weasel
'sly character' is the definition.
(I've seen this before)
'western given help by lawman at first' is the wordplay.
'western' becomes 'w'.
'given' means one lot of letters go next to another.
'help' becomes 'ease' (easing is a kind of helping).
'by' says to put letters next to each other.
'at first' suggests taking the first letters.
The initial letter of 'lawman' is 'l'.
'w'+'ease'+'l'='WEASEL'
'in' acts as a link.
(Other definitions for weasel that I've seen before include "Small carnivore" , "Stoat-like mammal - treacherous type" , "Small fierce animal with slender body and reddish-brown fur" , "Proverbially deceitful mammal" , "Double-dealer" .)