Boring bird?
I believe the answer is:
woodpecker
This clue could be a double definition.
'boring' is the first definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'bird?' is the second definition.
(woodpecker is a kind of bird)
Can you help me to learn more?
(Other definitions for woodpecker that I've seen before include "Knocking bird" , "Tapping bird" , "Bird that drills holes" .)