Witness's rhymes with:
witnesses', witnesses', eyewitnesses, witnesses', bonuses, cardenas's, catacosinos's, ethnos's, eyewitnesses, guinness's, illnesses, kotsonis's, likenesses, menaces, minuses, salinas's, selinas's, tennis's, witnesses'
Witness's sounds like:
wadhams, wading, waiting, wedding, weddings, weeding, wetness, wetting, whitenack, whiteness, whitening, whiting, whitings, whitman's, whitney's, whitting, widening, widens, widing, wieting, witness, witness', witnesses, witnesses', witting, woodhams, wooding, woodmac, woodmansee