Entry 2 senses · 2 variants Webster, 1913 Disimprove · Dis·im·prove · IPA v. t. v. i. 01 v. t. To make worse; -- the opposite of improve. 1. To make worse; -- the opposite of improve.[R.] 02 v. i. To grow worse; to deteriorate. 1. To grow worse; to deteriorate.