1 syllable:
atz, bats, batse, batts, batz, blats, blatz, brats, bratz, cat's, cats, catts, ccats, chats, chatz, chatz', dats, datz, fats, flats, frats, gatts, gatz, glatz, gnats, grats, gratz, hat's, hats, hatz, jpats, kats, katz, katze, kratz, lats, lattes, latz, mats, mattes, matts, matz, nats, pat's, pats, patz, plats, platts, platz, pmd ats, prats, pratt's, pratts, rat's, rats, ratts, ratz, satz, scats, schatz, shatz, skats, slats, smats, smt ats, spats, spatz, splats, sprats, stats, statz, stratz, tatts, that's, thats, vats

2 syllables:
abats, acats, adats, and that's, annats, arhats, at-bats, aussatz, awstats, bathmats, bearcats, begats, brickbats, bullbats, chitchats, combats, cowpats, cushats, diktats, dingbats, doormats, ducats, einsatz, ex-pats, expats, fiat's, fiats, flugplatz, formats, haemat-, hardhats, hauptsatz, hellcats, hepcats, hi-hats, high-hats, housecats, jurats, kid-e-cats, labatt's, mapats, marktplatz, meerkats, mudcats, mudflats, numbats, oshatz, parkplatz, placemats, polecats, rugrats, sabbats, sadat's, spielplatz, tomcats, whinchats, wildcats, wombats, yachats, zusatz

3 syllables:
achromats, acrobats, aerostat's, aerostats, apparats, appestats, arbeitsplatz, assignats, autocrats, automats, badavatz, bebelplatz, bodensatz, bodenschatz, bureaucrats, caveats, chemostats, cmats, copycats, coseratz, cryostats, datensatz, democrat's, democrats, democrats', diplomat's, diplomats, diplomats', dixiecrats, firebrats, habitat's, habitats, haemostats, hemostats, laundromats, marienplatz, photostats, pitapats, plutocrats, pussycats, reformats, rheostats, rosenblatts, scaredy-cats, technocrats, theocrats, thermostats, thundercats, umschlagplatz, ziggurats

4 syllables:
aristocrats, he-man/thundercats, meritocrats, physiocrats, siderostats

5 syllables:
8 out of 10 cats, alexanderplatz, bacteriostats, coccidiostats, image file formats, microhabitats, the aristocats

1 syllable:
lass, bass, class, kvass, pass, masse, gas, chasse, wrasse, grass, tasse, glass, brass, das, gras, ass, mass, sass

2 syllables:
ground bass, plate glass, striped bass, high mass, tape grass, bear grass, low mass, string bass, surpass, field glass, foie gras, bent grass, alsace, stained glass, impasse, harass, ground glass, rock bass, star grass, red brass, hand glass, lead glass, amass, cut glass, first-class, crevasse, alas, couch grass, form class, air gas, coal gas, tear gas, crown glass, milk glass, nerve gas, word class, rye grass, quartz glass, watch glass, sea bass, quack grass, lyme grass, shot glass, screen pass, third class, nut grass, morass, witch grass, marsh gas, bunch grass, rest mass, crab grass, en masse, pier glass, age class, sword grass, high brass, hair grass, flint glass, air mass, black bass, town gas, first class, art class, barn grass, bay grass, beer glass, bell glass, blow gas, broom grass, bur grass, camass, cloud grass, contrasts, cord grass, deer grass, dog grass, donbass, flute glass, forecasts, goat grass, goose grass, hall pass, high-class, ice mass, june grass, life class, love grass, low-class, low brass, make pass, means grass, pin grass, plume grass, quick grass, reed grass, rhodes grass, rice grass, silk grass, slough grass, smut grass, soft glass, stone bass, sweet grass, switch grass, wild ass, wool grass, yard grass

3 syllables:
thorough bass, pampas grass, figured bass, ideal gas, perfect gas, wire glass, bagasse, safety glass, upper class, inert gas, naval brass, mardi gras, boarding pass, middle class, social class, laughing gas, arrow grass, working class, cabin class, lower class, water glass, orchard grass, channel bass, object glass, looking glass, alpha brass, poison gas, middle-class, water gas, barley grass, double bass, bottled gas, cotton grass, mustard gas, forward pass, second class, noble gas, ruling class, cartridge brass, panic grass, barnyard grass, tourist class, bearing brass, black sea bass, blowing gas, bottle grass, brandy glass, bristle grass, broom beard grass, carpet grass, china grass, curly grass, devil grass, double-bass, drinking glass, english class, fescue grass, finger grass, fountain grass, foxtail grass, freshman class, grama grass, harding grass, jenny ass, junior class, liqueur glass, lower-class, manna grass, meadow grass, mountain pass, old witch grass, opal glass, orange grass, pane of glass, penny grass, pepper grass, physics class, piece of ass, prairie grass, ribbon grass, rock sea bass, salt reed grass, sea lyme grass, senior class, sewer gas, sheet of glass, silver grass, sophomore class, sour grass, tall oat grass, tumble grass, upper-class, velvet grass, whitlow grass, wild oat grass, windmill grass, wire grass, working-class, yellow bass

4 syllables:
atomic mass, canary grass, inertial mass, venetian glass, optical glass, center of mass, buffalo grass, snake in the grass, natural gas, bahia grass, bermuda grass, lateral pass, soluble glass, sergeant first class, producer gas, volcanic glass, alkali grass, bahama grass, cereal grass, chemistry class, creeping soft grass, crested wheat grass, domestic ass, egyptian grass, evergreen grass, feather reed grass, freshwater bass, giant star grass, immigrant class, levy en masse, major form class, manila grass, natural glass, pain in the ass, poverty grass, ravenna grass, reed meadow grass, shatterproof glass, spotted black bass, sunday school class, tall meadow grass, velvet bent grass, water star grass, weeping love grass

5 syllables:
laminated glass, magnifying glass, admiralty brass, african love grass, african wild ass, alligator grass, australian reed grass, biology class, common cotton grass, creeping windmill grass, graduating class, hairy finger grass, hungarian grass, japanese lawn grass, kentucky black bass, korean lawn grass, pheasant under glass, reed canary grass, yellow bristle grass

6 syllables:
relativistic mass, conservation of mass, gravitational mass, american star grass, carbon monoxide gas, european dune grass, fairway crested wheat grass, japanese carpet grass, korean velvet grass

7 syllables:
relative atomic mass, interplanetary gas

8 syllables:
relative molecular mass, liquefied petroleum gas, law of conservation of mass