Liable to change, inconsistent (8)
I believe the answer is:
variable
This clue is a double definition.
'liable to change' is the first definition.
(I've seen this before)
'inconsistent' is the second definition.
(associated in meaning)
(Other definitions for variable that I've seen before include "Inconsistent" , "Not steady or regular" , "mathematician's expression" , "Changeable or inconstant" , "Prone to change" .)