Improved rhymes with:
unimproved, unimproved, approved, disapproved, disproved, proved, unapproved, unimproved, unproved, approved, disapproved, disproved, proved, unapproved, unimproved, unproved
unimproved, unimproved, approved, disapproved, disproved, proved, unapproved, unimproved, unproved, approved, disapproved, disproved, proved, unapproved, unimproved, unproved