Tall dog at this point knocked over by Spooner (9)
I believe the answer is:
deerhound
'this point knocked over by spooner' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'tall dog' is the wordplay.
'tall' becomes 'deer' (I am not sure about this - if you are sure you should believe this answer much more).
'dog' becomes 'hound' (hound is a type of dog).
'deer'+'hound'='DEERHOUND'
'at' is the link.
Can you help me to learn more?
(Another definition for deerhound that I've seen is " Nude horde (anag) - dog".)