Akademik

noncancellable
adjective abiding, durable, indelible, ineffaceable, irrepealable, irreversible, lasting, nonabolishable, nonannullable, nonerasable, nonrescindable, nonretractable, nonreversible, permanent, unchangeable, undestroyable, unquashable, unvoidable associated concepts: noncancellable clause

Burton's Legal Thesaurus. . 2006