late 14c., "liable to change," from Latin mutabilis "changeable," from mutare "to change," from PIE root *mei- (1) "to change, go, move," with derivatives referring to the exchange of goods and services as regulated by custom or law (compare Latin mutuus "done in exchange").
the mutable ways of fortune
the fickle and mutable nature of truth
a mutable substance
mutable weather patterns
a mutable foreign policy
It is likely, too, that the chromosomes of all eubacteria are as mutable as that of E. coli
musteline
muster
mustn't
musty
mutability
mutable
mutagen
mutant
mutate
mutation
mutatis mutandis