Naval section of the horse artillery (3)
I believe the answer is:
sea
'naval section' is the definition.
The definition and answer can be both natural objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'of the horse artillery' is the wordplay.
'of' indicates a hidden word.
'SEA' is hidden in the letters of 'the horse artillery'.
Can you help me to learn more?
(Other definitions for sea that I've seen before include "Eg, Aral, Ross, Irish" , "that's easily reached from Dover?" , "Caspian, e.g." , "The tide" , "Watery expanse" .)