Flightless seabird (7)
I believe the answer is:
penguin
'flightless seabird' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for penguin that I've seen before include "King or emperor?" , "King's an example" , "Waddling bird" , "Flightless seabird" , "Flightless sea bird" .)