Acrobat's equipment relative has kept very cool (8)
I believe the answer is:
unicycle
'acrobat's equipment' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'relative has kept very cool' is the wordplay.
'relative' becomes 'uncle' (uncle is a kind of relative).
'has' is an insertion indicator.
'kept very cool' becomes 'icy' (I can't justify this - if you can you should believe this answer much more).
'uncle' enclosing 'icy' is 'UNICYCLE'.
Can you help me to learn more?
(Other definitions for unicycle that I've seen before include "that requires someone well-balanced in control" , "form of transport" , "One saddled" , "One-wheeler" , "One-wheeled conveyance" .)