noun increase; growth; progress; advance.
2. improvement ·noun a useful addition to, or modification of, a machine, manufacture, or composition.
3. improvement ·noun valuable additions or betterments, as buildings, clearings, drains, fences, ·etc., on premises.
4. improvement ·noun the state of being improved; betterment; advance; also, that which is improved; as, the new edition is an improvement on the old.
5. improvement ·noun the act of improving; advancement or growth; promotion in desirable qualities; progress toward what is better; melioration; as, the improvement of the mind, of land, roads, ·etc.
6. improvement ·noun the act of making profitable use or applicaton of anything, or the state of being profitably employed; a turning to good account; practical application, as of a doctrine, principle, or theory, stated in a discourse.