Weaving tires poor Bottom (9)
I believe the answer is:
posterior
'bottom' is the definition.
('posterior' can be a synonym of 'bottom')
'weaving tires poor' is the wordplay.
'weaving' indicates anagramming the letters.
'tires'+'poor'='tirespoor'
'tirespoor' anagrammed gives 'POSTERIOR'.
(Other definitions for posterior that I've seen before include "Backside" , "Hindquarters" , "Further back; bottom" , "Behind" , "later" .)