Horse possibly watched on TV (3)
I believe the answer is:
bay
'horse' is the definition.
(bay is a kind of horse)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bay that I've seen before include "Indentation of a shoreline" , "Chestnut" , "Botany, Galway or Tampa" , "Inlet; shrub" , "laurel maybe" .)