An animal uprising, overturning slaughterhouse (8)
I believe the answer is:
abattoir
'slaughterhouse' is the definition.
('abattoir' can be a synonym of 'slaughterhouse')
'an animal uprising overturning' is the wordplay.
'an' becomes 'a'.
'animal' becomes 'bat' (bat is a kind of animal**).
'uprising' becomes 'riot' (I've seen this before).
'overturning' shows that the letters should be reversed in order.
'riot' in reverse letter order is 'toir'.
'a'+'bat'+'toir'='ABATTOIR'
(Other definitions for abattoir that I've seen before include "Building for butchering animals" , "Building used for butchery" , "It might make a killing" , "stunning location" , "Animal slaughter-house" .)