Youngest rhymes with:
longest, nagengast, schrecengost, schreckengost, schrecongost, strongest, aug, august, auguste, biggest, longest, nagengast, schrecengost, schreckengost, schrecongost, strongest, winningest, wolgast
Youngest sounds like:
yamagata, yamashita, yanked, yingst, yongchaiyudh, youngquist