Accept dog finds butterfly (11)
I believe the answer is:
swallowtail
'butterfly' is the definition.
(I've seen this before)
'accept dog' is the wordplay.
'accept' becomes 'swallow' (I've seen this before).
'dog' becomes 'tail' (synonyms).
'swallow'+'tail'='SWALLOWTAIL'
'finds' acts as a link.
(Other definitions for swallowtail that I've seen before include "Butterfly" , "coat" , "In circle, mythical snake does" , "insect" .)