1.Definition: capable of or tending to change in form or quality or nature
"A mutable substance", "Mutable weather patterns", "A mutable foreign policy"
2.Definition: prone to frequent change; inconstant
"The fickle and mutable nature of truth", "The mutable ways of fortune"
3.Definition: tending to undergo genetic mutuation
"It is likely, too, that the chromosomes of all eubacteria are as mutable as that of E. coli"