Watch a big bee, cuckoo, and butterfly (7-5)
I believe the answer is:
cabbage white
'butterfly' is the definition.
(I've seen this before)
'watch a big bee cuckoo' is the wordplay.
'cuckoo' indicates anagramming the letters.
'watch'+'a'+'big'+'bee'='watchabigbee'
'watchabigbee' with letters rearranged gives 'CABBAGE-WHITE'.
'and' is the link.
(Other definitions for cabbage white that I've seen before include "We bag ice bath (anag) - butterfly" , "Common British butterfly" , "summer visitor" , "Common pest butterfly" , "insect" .)