1 syllable:
ass, bass, basse, blass, bras, brass, brasse, cas, cass, casse, chass, chasse, class, classe, crass, crasse, das, dass, dcass, dclass, ddass, drass, fahs, fass, fasse, frass, gas, gass, gasse, glas, glasse, grass, grasse, hass, jass, kass, kasse, klas, klass, klasse, kras, krass, kvass, lass, lasse, mass, mass., masse, nass, nasse, pass, plas, plass, plasse, prass, ras, rasse, sas, sass, sasse, shass, strass, strasse, tass, tasse, trass, trasse, vass, wrass, wrasse, yass, yeahs

2 syllables:
a-class, aairpass, admass, airgas, airmass, alas, alass, alsace, amass, amcas, anlass, audace, bad-ass, badass, band-pass, bandpass, bare-ass, beargrass, bell-glass, bent-grass, bentgrass, besace, big-ass, bindass, bluegrass, bromegrass, bumpass, bunchgrass, burgrass, by-pass, bypass, camass, cane-grass, chagas, cheatgrass, classpass, contrasts, cordgrass, couch-grass, couchgrass, crabgrass, crevasse, cut-glass, cut-grass, cutgrass, damasse, declass, declasse, deergrass, depass, donbass, dumb-ass, e-glass, e-zpass, eagrass, ecass, eelgrass, egg-glass, emass, eyeglass, fat-ass, fatass, fieldglass, filasse, finglas, first-class, forecasts, forpass, fourth-class, goose-grass, groundmass, half-ass, harass, hard-ass, hardass, hardbass, high-class, hoofdklasse, i-pass, impasse, ipass, jackass, keepass, kick-ass, kickass, kiss-ass, knotgrass, kompass, kuzbass, lambastes, landmass, lard-ass, lardass, lastpass, lovegrass, low-class, lowpass, metglas, miass, midgrass, molasse, morass, navras, newgrass, nordpass, nutgrass, ofgas, outclass, outlasts, outpass, owlglass, piepgras, plate-glass, portass, potass, quackgrass, recas, repass, ribgrass, ricegrass, rush-grass, rushgrass, rye-grass, ryegrass, sambass, sandglass, sawgrass, sea-grass, seabass, seagrass, serfass, she-ass, short-grass, shortgrass, silkgrass, smart-ass, smartass, snodgrass, speargrass, spyglass, stained-glass, stormglass, sub-bass, subclass, sunglass, sunpass, surpass, switchgrass, tall-grass, tallgrass, third-class, tight-ass, timepass, top-class, transpass, trespass, tresspass, umass, vanasse, velas, verglas, vorace, watch-glass, watchglass, wheat-grass, wheatgrass, wineglass, wiregrass, wise-ass, witchgrass, world-class, worldclass, worldpass, yankass, yardgrass

3 syllables:
after-grass, aftergrass, ahnenpass, arrowgrass, autopass, bierglas, bio-mass, boardingpass, botopass, bottle-grass, bottlegrass, bristlegrass, burning-glass, candlemas, candlemass, candy-ass, cotton-grass, curtelasse, dallisgrass, demi-tasse, double-bass, efficace, energas, europass, fiberglas, fiberglass, fibreglass, galloglass, gallowglass, gangstagrass, goosegrass, hardinggrass, hippocras, hoppergrass, hour-glass, hourglass, interclass, ipocras, isinglass, itar-tass, jenny-ass, johnsongrass, lemongrass, looking-glass, lower-class, madecass, martinmas, masterclass, meadow-grass, meadowgrass, metaclass, middle-class, middleclass, middlemas, montparnasse, motorbass, moviepass, overclass, overpass, peppergrass, perspicace, plexiglas, plexiglass, psycho-pass, push-to-pass, quatermass, rankin/bass, ravenglass, ripple-grass, sassafras, sassafrass, scurvy-grass, second-class, shangri-las, sonderclass, sparagrass, sparrowgrass, superclass, supergrass, tarantass, thorough-bass, underclass, underpass, untertasse, upper-class, upperclass, weatherglass, weierstrass, wiseass, working-class, xmass, ypocras

4 syllables:
africa/brass, amerigas, canary-grass, ecclesiastes, scorpion-grass, timothy-grass

5 syllables:
economyclass, lower-middle-class, upper-lower-class, upper-middle-class

1 syllable:
spats, hats, katz, flats, bats, cats, fats, rats, pat's, that's