Aboveboard rhymes with:
baseboard, billboard, blackboard, cardboard, checkerboard, chessboard, chipboard, clapboard, clipboard, containerboard, dartboard, dashboard, fiberboard, fibreboard, fingerboard, floorboard, hardboard, headboard, inboard, keyboard, linerboard, mopboard, onboard, outboard, overboard, paperboard, pegboard, plasterboard, pressboard, scoreboard, seaboard, shipboard, skateboard, smorgasbord, snowboard, springboard, storyboard, surfboard, switchboard, wallboard, washboard
Aboveboard sounds like:
abert, abhorred, aboard, abort, aborted, abroad, aburto, afford, afforded, afraid, afridi, apart, apartheid, aphrodite, appeared, appert, aubert, averett, averette, averitt, avert, averted, avrett