Undress rhymes with:
dress, redress, aggress, bress, bresse, cress, depress, digress, distress, dress, egress, express, express', fluoresce, gress, impress, kress, kresse, l'express, oppress, press, press', presse, redress, repress, ress, stress, suppress, transgress, tress
Undress sounds like:
under-age, underage, undercook, undergo, undergoes, undersea, underseas, underuse