Quast rhymes with:
bossed, bost, brost, cost, dost, drost, jost, knost, kost, pfost, prost, rost, trost
Quast sounds like:
qiaotou, quad, quade, quaid, quashed, quesada, quest, quezada, quickest, quid, quiet, quieted, quiett, quijada, quist, quit, quite, quito, quixote, quizzed, quota, quote, quoted