Ornamental cloth and headgear being worn to hide a knight turning up (9)
I believe the answer is:
caparison
'ornamental cloth' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'headgear being worn to hide a knight turning up' is the wordplay.
'headgear' becomes 'cap' (cap is a kind of headgear).
'being worn' becomes 'on' (as in having clothes on).
'to hide' means one lot of letters goes inside another.
'a knight turning up' becomes 'aris' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'cap'+'on'='capon'
'capon' going around 'aris' is 'CAPARISON'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for caparison that I've seen before include "covering for the Shires?" , "Decorative covering for a horse" , "rich gear" , "Ornamental covering over a horse's saddle or harness" , "What a horse may have on" .)