Loudest rhymes with:
proudest, blondest, buddhist, coldest, eldest, encyclopedist, fondest, grandest, hardest, kindest, methodist, mildest, modest, oddest, oldest, orthopedist, prejudiced, propagandist, proudest, rudest, saddest, sadist, shrewdest, soundest, stupidest, weirdest, widest
Loudest sounds like:
latched, latest, liddicoat, litigate, litigated, lodged