Brooding of acrobat isn’t unusual (11)
I believe the answer is:
abstraction
'brooding' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'acrobat isn't unusual' is the wordplay.
'unusual' indicates an anagram.
'acrobat'+'isnt'='acrobatisnt'
'acrobatisnt' anagrammed gives 'ABSTRACTION'.
'of' is the link.
Can you help me to learn more?
(Other definitions for abstraction that I've seen before include "reverie" , "form of treatment" , "Preoccupation" , "Theoretical concept - removal" , "wool-gathering?" .)