Undo rhymes with:
undue, katmandu, undue, adieu, ado, badu, chengdu, deux, dew, do, doo, douwe, du, due, katmandu, ledoux, long-overdue, outdo, overdo, overdue, pas-de-deux, perdue, purdue, redo, seydoux, subdue, undue, urdu, yabbadabbadoo
Undo sounds like:
uinta, unaided, unamended, unanimity, unaudited, und, undated, undid, undue, unedited, unheeded, unimate, unimedia, uninitiated, unit, unita, unite, united, unity, unmade, unmanned, unmet, unnamed, unneeded, unted, untidy, untie, untied, untiedt, unto, unwanted, unwed, unwind, unwound