Quail is a bird seen around lake (6)
I believe the answer is:
flinch
'quail' is the definition.
(I've seen this before)
'bird seen around lake' is the wordplay.
'bird' becomes 'finch' (finch is a kind of bird**).
'seen around' means one lot of letters goes inside another.
'lake' becomes 'l'.
'finch' going around 'l' is 'FLINCH'.
'is a' acts as a link.
(Other definitions for flinch that I've seen before include "Shrink back with fear" , "Shrink back (out of pain/fear)" , "Cower, baulk" , "Draw back in shock" , "Recoil from pain, surprise etc" .)