2 syllables:
-aster, -master, aster, astor, astur, bastar, baster, blaster, caster, castor, cast her, craster, dastar, dastur, drmaster, faster, gaster, haster, hastur, jaster, kaster, kastor, laster, lastre, master, mastor, passed her, paster, pastor, past her, pasztor, pflaster, plaster, raster, sastre, shaster, vaster

3 syllables:
albastar, ancaster, bandmaster, bargemastter, barmaster, beachmaster, beach aster, beastmaster, beemaster, beplaster, bergmaster, bog aster, botmaster, brewmaster, broadcaster, buckmaster, burghmaster, burgmaster, bushmaster, cadaster, canaster, chargemaster, chessmaster, cluemaster, cockmaster, contraster, court-plaster, court plaster, craftsmaster, diaster, disaster, divemaster, dockmaster, doncaster, drillmaster, drill master, emplaster, fightmaster, firemaster, flamemaster, forecaster, gamemaster, games-master, gamesmaster, gangmaster, goodpaster, grandmaster, grassmaster, hackmaster, headmaster, heath aster, hoffmaster, housemaster, huffmaster, ink master, jazzmaster, jumpmaster, lancaster, landmaster, linecaster, loadmaster, lockmaster, macmaster, mcmaster, micraster, mint-master, mixmaster, netcaster, newscaster, nightcaster, old master, past master, paymaster, piaster, pilaster, pineaster, podcaster, postmaster, quizmaster, rangemaster, remaster, ringmaster, roadmaster, rolemaster, roughcaster, rush aster, sandblaster, saymaster, schoolmaster, scoutmaster, sea aster, sheepmaster, shinplaster, shipmaster, slavemaster, smooth aster, solaster, spellcaster, sperm-aster, sportscaster, sportsmaster, spymaster, stainmaster, stairmaster, starved aster, stiff aster, stylaster, surfcaster, tadcaster, taskmaster, thrustmaster, toastmaster, trackmaster, trainmaster, two-master, unpastor, view-master, warmaster, waycaster, webcaster, webmaster, weighmaster, wharfmaster, wheremaster, whoremaster, wood aster, workmaster, wreck-master, yachtmaster, yardmaster

4 syllables:
adelaster, alabaster, amphiaster, ari aster, azure aster, boroughmaster, burghermaster, burgomaster, bushy aster, china aster, choirmaster, concert-master, concertmaster, countercaster, criticaster, dancing-master, genus aster, genus castor, ghettoblaster, golden aster, harbormaster, harbourmaster, ironmaster, james acaster, jim buckmaster, judomaster, lath and plaster, medicaster, mesogaster, mustard plaster, myocastor, new york aster, oleaster, overmaster, prairie aster, puppetmaster, puzzlemaster, quartermaster, question master, rebroadcaster, riding master, sailing master, sambomaster, servicemaster, singing-master, small white aster, snallygaster, southern aster, stationmaster, sticking-plaster, sticking plaster, sticky aster, stratocaster, supertaster, telecaster, ticketmaster, undermaster, watermaster, weathercaster, white wood aster, willow aster, witticaster

5 syllables:
adhesive plaster, avro lancaster, bhopal disaster, calico aster, cornflower aster, dvdisaster, goldilocks aster, grammaticaster, henry mcmaster, house of lancaster, interpilaster, late purple aster, mojave aster, new england aster, politicaster, property master, rattlesnake master, solenogaster, tansy leaf aster, upland white aster, verticillaster, weather forecaster, white prairie aster

6 syllables:
2008 k2 disaster, aromatic aster, city of lancaster, hairy golden aster, hillsborough disaster, paco cabanes pastor, prairie golden aster

7 syllables:
eastern silvery aster, kursk submarine disaster, maryland golden aster, television newscaster, the who concert disaster, western silvery aster

8 syllables:
oriental alabaster, perennial salt marsh aster

9 syllables:
1955 le mans disaster, costa concordia disaster, tenerife airport disaster

12 syllables:
1996 mount everest disaster

3 syllables:
nougat bar, two-bagger