To many a duck, a variety of heron? (7)
I believe the answer is:
'to many a duck a variety of heron?' is the definition.
I can't tell whether this defines the answer.
'many a duck a variety of heron?' is the wordplay.
'many' becomes 'm' (Roman numeral for a thousand).
'a duck' becomes 'o' (resembles zero - 'duck' in cricket).
'a variety of' indicates anagramming the letters.
'heron' is an anagram of 'orhen'.
'm'+'o'+'orhen'='MOORHEN'
Can you help me to learn more?
(Other definitions for moorhen that I've seen before include "Medium-sized, blackish aquatic bird with long toes" , "pond bird" , "Female red grouse or waterfowl" , "Water bird" , "Black waterbird" .)