Bird left in a snare (6)
I believe the answer is:
linnet
'bird' is the definition.
(linnet is a kind of bird)
'left in a snare' is the wordplay.
'left' becomes 'l' (common abbreviation).
'a snare' becomes 'net' (I've seen this before**).
'l'+'in'+'net'='LINNET'
(Other definitions for linnet that I've seen before include "Type of finch" , "Songster" , "Common finch" , "Winger" , "House finch" .)