1 [U] ~ (in / on / to sth) the act of making sth better; the process of sth becoming better:
Sales figures continue to show signs of improvement. * There is still room for improvement in your work. * We expect to see further improvement over the coming year.
2 [C] ~ (in / on sth) a change in sth that makes it better; sth that is better than it was before:
a significant / substantial / dramatic improvement * a slight / steady improvement * an improvement in Anglo-German relations * This is a great improvement on your previous work. * improvements to the bus service * home improvements (= changes that are made to a house, that increase its value)
HELPNOTE Home improvement is [U] in AmE.
