Kerth rhymes with:
kurth, berth, birth, dearth, earth, firth, fuerth, furth, gerth, girth, hirth, kurth, mirth, perth, rebirth, unearth, wentworth, werth, wirth, worth, wurth
Kerth sounds like:
karat, karate, karet, kerwood, keyword, keyworth, kirt, kiryat, korda, koret, kort, korte, korth, koshered, krat, kratt, kraut, krauth, kredit, kriete, krout, kuhrt, kurd, kuroda, kurt, kurth