1 syllable:
-eous, -less, -tious, brosse, brus, bruss, bus, buss, busse, cba sce, clous, croise, crous, cr ccis, cus, cuss, fluss, fress, fuhs, fuss, gres gris, gruss, gus, guss, huss, klus, krus, kus, kuss, kyuss, lsass, ltspice, muhs, musse, nuss, nusse, pholas, plisse, plus, pluss, prma hs, prus, pruss, pspice, pus, puss, pvris, qwg cis, rndis, rus, russ, russe, scgis, schluss, schuss, shas, sluss, smbus, smr mis, struss, stuss, sus, suss, swisse, thrace, thus, thuss, tm mis, trus, truss, ttp hus, tusse, us, vl-bus, vtmis, wass, whmis, wuss, xus

2 syllables:
a-plus, abrus, adjusts, baitbus, barfuss, boltbus, careplus, catbus, concuss, cost-plus, cottbus, discuss, donruss, einfluss, erdnuss, excuss, funplus, ghattas, goldfus, gyruss, homerus, hpcode-plus, huertas, incuss, kingtruss, kottbus, loveplus, mistrusts, narus, netbus, non-pluss, nonplus, nonpluss, oneplus, opruss, pageplus, percuss, pileus, postbus, rambus, redbus, schoolbus, school bus, shortbus, succuss, untruss, vanhuss, walnuss, wrightbus

3 syllables:
adblock plus, banderas, camping bus, charlotte russe, cytisus, eurailpass, express bus, genus sus, gloomy gus, haselnuss, hasenfus, interfluous, muckenfuss, okenfuss, papenfuss, pelorus, repercuss, sasha luss, shuttle bus, subterfluous, superfluous, treasonous

4 syllables:
eleven-plus, the venture bros.

5 syllables:
simulations plus

6 syllables:
chamaecytisus

3 syllables:
shiftiness, brininess, bitchiness, stickiness, sliminess, tipsiness, wittiness, thriftiness, spiciness, flimsiness, trickiness, shininess, tidiness, dizziness, silliness, iciness, mistiness, filthiness, ginglymus, springiness, griminess, friskiness, skinniness, windiness, pitiless, pithiness, dinginess, guiltiness, chilliness, silkiness, crispiness, cyprinus, giddiness, gimpiness, kindliness, minginess, prettiness, riskiness, sissiness, slipperiness, stinkiness, wiggliness, wiliness

4 syllables:
untidiness, fidgetiness, callicebus