A rage rejected by a lean American trapeze artist (9)
I believe the answer is:
aerialist
'american trapeze artist' is the definition.
(US term for a trapeze acrobat)
'a rage rejected by a lean' is the wordplay.
'rage' becomes 'aire' (I am not sure about this - if you are sure you should believe this answer much more).
'rejected' says the letters should be written in reverse.
'by' says to put letters next to each other.
'a lean' becomes 'list' (I've seen this before).
'aire' backwards is 'eria'.
'a'+'eria'+'list'='AERIALIST'
Can you help me to learn more?
(Other definitions for aerialist that I've seen before include "Highly-regarded performer" , "trapeze artist" , "skier" , "Trapeze acrobat" .)