Screech of curlew at a cuckoo (9)
I believe the answer is:
caterwaul
'screech' is the definition.
(caterwauling is a kind of screeching)
'curlew at a cuckoo' is the wordplay.
'cuckoo' indicates anagramming the letters.
'curlew'+'at'+'a'='curlewata'
'curlewata' anagrammed gives 'CATERWAUL'.
'of' acts as a link.
(Other definitions for caterwaul that I've seen before include "Howl like a feline" , "Howl like cat" , "Sound of moggy" , "howl unpleasantly" , "Sound catty" .)