Sea-horse? (3)
I believe the answer is:
bay
'horse?' is the definition.
(I know that bay is a type of horse)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for bay that I've seen before include "Sea inlet" , "Howl" , "Small alcove" , "laurel maybe" , "Inlet; shrub" .)