Deer confused about one water fowl (5)
I believe the answer is:
eider
'water fowl' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'deer confused about one' is the wordplay.
'confused' indicates an anagram.
'about' means one lot of letters goes inside another.
'one' becomes 'I' (Roman numeral).
'deer' is an anagram of 'eder'.
'eder' going around 'i' is 'EIDER'.
Can you help me to learn more?
(Other definitions for eider that I've seen before include "Downy sea duck" , "Sea bird" , "Northern sea duck" , "Sea duck with soft down" , "Duck known for down" .)