Flatter rhymes with:
blatter, clatter, latter, platter, schlatter, slatter, splatter, antimatter, attar, batter, blatter, chatter, chitterchatter, clatter, fatter, hatter, latter, matter, mcfatter, mcphatter, natter, patter, platter, sater, satter, scatter, schlatter, shatter, slatter, smatter, spatter, splatter, tatar, tatter, vanatter, vannater, vannatter, vatter
Flatter sounds like:
falter, felder, felter, fielder, filter, flater, flattery, flatware, floater, floodwater, flutter, folder, fulwider