King, maybe, unable to take flight (7)
I believe the answer is:
penguin
'king' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for penguin that I've seen before include "Flightless marine bird" , "Waddling bird" , "swimmer" , "King's an example" , "Flightless seabird" .)