Addition rhymes with:
edition, erudition, expedition, extradition, tradition, audition, condition, edition, erudition, expedition, extradition, precondition, recondition, rendition, sedition, tradition
Addition sounds like:
adam, adame, adami, adamina, adamo, adan, aden, adena, adenine, adham, adin, adina, adine, adman, admen, adnan, adney, adon, adonia, aetna, aidan, aithne, aiton, atamian, aten, athena, athenaeum, atheneum, athenian, atom, aton, atone, attain, attune, auden, audino, audition, audwin, auten, autoimmune, auton, autonomy, autumn, aydin