mutable
adjective(mu-ta-ble)
capable of or tending to change in form or quality or nature
Examples:
A mutable substance. 
Mutable weather patterns. 
A mutable foreign policy. 
mutable
adjective(mu-ta-ble)
prone to frequent change; inconstant
Examples:
The fickle and mutable nature of truth. 
The mutable ways of fortune. 
mutable
adjective(mu-ta-ble)
tending to undergo genetic mutuation
Examples:
It is likely, too, that the chromosomes of all eubacteria are as mutable as that of E. coli.