say it: im-PROOV-muhnt
improvement is a noun meaning "a change for the better; progress in development". It carries 3 recorded senses.
a change for the better; progress in development
the act of improving something
“their improvements increased the value of the property”
a condition superior to an earlier condition
“the new school represents a great improvement”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for improvement come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.