Widest rhymes with:
blondest, buddhist, coldest, eldest, encyclopedist, fondest, grandest, hardest, kindest, loudest, methodist, mildest, modest, oddest, oldest, orthopedist, prejudiced, propagandist, proudest, rudest, saddest, sadist, shrewdest, soundest, stupidest, weirdest
Widest sounds like:
watched, wedged, wedgewood, wedgwood, wetsuit, wettest, whiteside, whitest, whitewashed, whitsett, whitsitt, widget, withstood, woodshed, woodside