Synonyms for Improve:

n.

help. convalesce, recuperate, health. improve (noun)
ameliorate, meliorate, better.

v.

correct (verb)
patch, alter, correct, remedy, repair, revise, amend, fix, adjust, rectify.
improve (verb)
elaborate, embellish, garnish, further, better, upgrade, enhance, refine, renovate, progress, enrich, advance.
make or become better (verb)
increase, promote, meliorate, progress, perk up, civilize, touch up, update, mend, better, ameliorate, lift, augment, amend, advance, rectify, recover, elevate, convalesce, pick up, edit, cultivate, revise, shape up, polish, come around, straighten out, enhance, refine, develop, rally, sharpen, help, raise, revamp, look up, boost, correct, upgrade, recuperate.
progress (verb)
proceed, make headway.
restore (verb)
rejuvenate, mend, revive, reconstitute, cure, heal, recondition, rehabilitate, darn, overhaul, restore.

Other synonyms:

promote, convalesce, regenerate, develop, shape up, sharpen, improve on, revitalize, ease off. cultivate, come-on, perk up, snap out of it, recover, come along, grow, recuperate. rally, catch up. look up. help, elevate. mature. gain. pick up, raise. lift. cheer
perk up.
come on
make headway.
correct
shape up, straighten out.
enlighten
civilize.
go forward
make progress.
restore
recondition.

Usage examples for improve

  1. To Edison life is not only a grand opportunity to find out things by experiment, but, when found, to improve them by further experiment. – Edison, His Life and Inventions by Frank Lewis Dyer and Thomas Commerford Martin
  2. If I thought Mr. Flint would like it, I'd get Kate M'Carty to come in some day and help us; and I think we could greatly improve his home. – The Lamplighter by Maria S. Cummins