Low-flying hunter (3)
I believe the answer is:
owl
'hunter' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'low-flying' is the wordplay.
'flying' is an anagram indicator.
'low' is an anagram of 'OWL'.
Can you help me to learn more?
(Other definitions for owl that I've seen before include "Solemn person" , "Creature" , "Athena's bird" , "Member of Parliament" , "Low kind of wise bird" .)