Elapse rhymes with:
claps, collapse, flaps, lapps, laps, lapse, relapse, slaps, apps, cap's, capps, caps, chaps, claps, collapse, crapps, craps, flaps, gap's, gaps, japs, kappes, kaps, knapp's, lapps, laps, lapse, maps, naps, perhaps, raps, relapse, saps, schnapps, scraps, slaps, snaps, straps, taps, traps, wraps, yaps, zaps
Elapse sounds like:
el-paso, elbows, elf's, elfish, ellipse, elopes, elves, elvis, elvis', elvis's