1 syllable:
--dash, -dash, /slash, asch, asche, ashe, basch, bash, bashe, bcache, bkash, brasch, brash, cache, cash, cashe, chash, clash, crash, crashh, dache, dasch, dash, drash, flasch, flasche, flash, frasch, gash, gcash, gnash, guasch, hasch, hash, kasch, kash, lasch, lasche, lash, masch, masche, mash, mdash, nash, nashe, ndash, pasche, pash, plash, rasch, rasche, rash, sash, shash, slash, smash, snash, spash, splash, stash, tasch, tasche, tash, thrash, trash, zcash

2 syllables:
abash, abrash, amash, atbash, ayyash, backflash, backlash, backslash, backsplash, badmash, barbash, bedash, berdash, bone-ash, boyash, budmash, cache-cache, cadash, calash, cardcash, chumash, cornbrash, corn tash, dealdash, disk cache, dotdash, drucksache, dubsmash, e-cash, earbash, ecash, emdash, encash, endash, ethash, eyelash, facemash, femslash, fiveash, flingsmash, food cache, furash, gate-crash, gatecrash, gnucash, gulasch, gytrash, habash, hack/slash, hashcash, head crash, heat flash, heat rash, hot flash, izhmash, jazzcash, jim rash, jordache, keysmash, kourbash, lagash, lavash, locash, lodash, lukash, metcash, michmash, mischmasch, mishmash, monash, monyash, moustache, mustache, mustasch, najash, nefasch, nicehash, non-cash, noncash, palash, pay cash, pearl-ash, pearlash, pistache, postcrash, potash, precrash, quamash, rehash, remache, rose-rash, saltash, shabash, shammash, shapash, skin rash, slapdash, squabash, starcrash, storm sash, subash, swung dash, syvash, taplash, timelash, tongue-lash, unlash, unsplash, whiplash, whitelash, white trash, yuzhmash

3 syllables:
100-yard dash, aftermash, agastache, aktentasche, al-ahbash, aquaslash, astrosmash, balderdash, battaash, bitcoin cash, calabash, calipash, callipash, compactflash, cybercash, diaper rash, digicash, dm-cache, eurotrash, frazer-nash, geocache, geohash, haberdash, hamantasch, hamantash, interdash, in a flash, kevin nash, kintpuash, macintrash, malagash, murmurhash, nettle-rash, nettle rash, overcash, overlash, pebble-dash, pebbledash, petty cash, photoflash, poor white trash, prickly-ash, ragabash, rosanne cash, rostselmash, sabretasche, shoulder flash, sideflash, sour mash, spartannash, spatterdash, splatterdash, stacey dash, starofash, succotash, suckatash, synchroflash, tsniitochmash, uralmash, white backlash, window sash

4 syllables:
caustic potash, electroclash, enkutatash, memory cache, shemhamphorasch

5 syllables:
geometry dash, metrowagonmash, pranitha subhash

8 syllables:
2020 stock market crash