Amendable

to alter, modify, rephrase, or add to or subtract from (a motion, bill, const-tution, etc.) by formal procedure:
congress may amend the proposed tax bill.
to change for the better; improve:
to amend one’s ways.
synonyms: ameliorate, better.
antonyms: worsen.
to remove or correct faults in; rectify.
to grow or become better by reforming oneself:
he amends day by day.
synonyms: improve, ameliorate.
antonyms: worsen.
contemporary examples

these contracts are transactional contracts, meaning they are amendable based on changes in program partic-p-tion.
jp morgan’s food stamp empire peter schweizer september 30, 2012

historical examples

when a conference committee report comes before the house, it is adopted or rejected in toto, as it is not divisible or amendable.
the cleveland era henry jones ford

verb (transitive)
to improve; change for the better
to remove faults from; correct
to alter or revise (legislation, a const-tution, etc) by formal procedure
v.

early 13c., “to free from faults, rectify,” from old french amender (12c.), from latin emendare “to correct, free from fault,” from ex- “out” (see ex-) + menda “fault, blemish,” from pie -mend- “physical defect, fault” (cf. sanskrit minda “physical blemish,” old irish mennar “stain, blemish,” welsh mann “sign, mark”).

supplanted in senses of “repair, cure” by its shortened offspring mend (v.). meaning “to add to legislation” (ostensibly to correct or improve it) is recorded from 1777. related: amended; amending.