Lasso used at lair (6)
I believe the answer is:
lariat
'lasso' is the definition.
(I know that lasso can be written as lariat)
'used at lair' is the wordplay.
'used' is an anagram indicator.
'at'+'lair'='atlair'
'atlair' anagrammed gives 'LARIAT'.
(Other definitions for lariat that I've seen before include "Rope with running loop at one end" , "Cowboy's rope, lasso" , "A cowboy's rope with noose" , "Mortar-spreading tool" , "Long noosed rope for catching animals" .)