Smoothness rhymes with:
abruptness, absoluteness, acuteness, adonis, aggressiveness, agribusiness, airworthiness, alertness, aloofness, alumnus, anas, androgynous, anise, anus, appropriateness, aquinas, arbitrariness, assertiveness, astuteness, asynchronous, attentiveness, attractiveness, awareness, awfulness, awkwardness, backwardness, badness, bagginess, baldness, barsness, bearishness, bigness, bitchiness, bitterness, bituminous, blackness, blandness, blastfurnace, bleakness, blessedness, blindness, bloatedness, blueness, bluntness, boldness, bonus, boorishness, bounciness, brashness, brazenness, brightness, bullishness, burness, business, callousness, calmness, cardenas, carelessness, cautiousness, cavernous, cheapness, chitinous, cleverness, clumsiness, cockiness, cohesiveness, coldness, colinas, colonus, combativeness, compactness, completeness, consciousness, contagiousness, contentiousness, contrariness, conus, coolness, correctness, coziness, craziness, creativeness, creditworthiness, crispness, cronus, crookedness, cuteness, cygnus, dangerousness, daphnis, darkness, deaconess, deadliness, deafness, decisiveness, defensiveness, directness, discontentedness, disingenuousness, distinctiveness, divisiveness, dizziness, dominus, dreariness, drowsiness, drunkenness, dryness, duenas, dullness, eagerness, earnestness, edginess, effectiveness, elusiveness, emptiness, enos, eunice, evenness, exogenous, eyewitness, fadness, faintness, fairness, farsightedness, fastness, fickleness, fidenas, firmness, fitness, flatness, fondness, foolishness, forcefulness, forgiveness, forthrightness, foulness, fractiousness, frankness, freshness, fullness, funniness, furnace, furnas, gainous, gauntness, gayness, gelatinous, gentleness, genus, ghastliness, givenness, glonass, gluttonous, goodness, governess, graciousness, greatness, greenness, grimness, guiness, guinness, hairiness, handedness, happiness, hardness, harkness, harmfulness, harness, harshness, hartness, hawkiness, healthiness, heinous, hellaciousness, helplessness, high-spiritedness, highness, hoarseness, holderness, holiness, homelessness, homesickness, homogenous, hopelessness, humanness, idleness, ignace, illness, indecisiveness, indigenous, ineffectiveness, inertness, innes, intravenous, inventiveness, janice, janus, jewishness, joblessness, johannes, jointness, jonas, keratoconus, kindness, kotsonis, kotsonis', larcenous, lateness, lawlessness, laziness, lenis, lessness, lightfastness, lightheadedness, lightness, likeness, linnas, linus, liveliness, loneliness, lousiness, low-spiritedness, luminous, macinnes, macinnis, madness, magnus, malvinas, marianas, mcginess, mcginness, mcginnis, mcginniss, mcguiness, mcguinness, mcinnes, mcinnis, mckiness, mckinnis, mcmanis, mcmannis, mcmanus, meanness, membranous, menace, minas, mindedness, minus, monotonous, monus, mountainous, mutinous, narrowness, nastiness, nearsightedness, neatness, nervousness, newness, niceness, niggardliness, nitrogenous, nonbusiness, nonpoisonous, nosiness, nothingness, numbness, oleaginous, ominous, oneness, onus, openness, orderliness, otherness, outrageousness, outspokenness, pandanus, parness, patroness, peacefulness, permissiveness, persuasiveness, petronas, pettiness, playfulness, poisonous, politeness, polygynous, pompousness, poor-spiritedness, possessiveness, powerlessness, preakness, preparedness, public-spiritedness, queasiness, quickness, quietness, raciness, randomness, ravenous, readiness, reasonableness, rebelliousness, recklessness, redness, remoteness, resistiveness, resourcefulness, responsiveness, restiveness, restlessness, restrictiveness, richness, righteousness, rightness, riskiness, robustness, roominess, roughness, rowdiness, rudeness, ruinous, ruthlessness, sadness, salinas, salinas', sameness, sandness, scantiness, secretiveness, selfishness, sensitiveness, separateness, seriousness, sethness, sexiness, shakiness, shallowness, sharpness, shortness, shrewdness, shyness, sickness, silliness, sinus, skittishness, slackness, sleepiness, sloppiness, slovenliness, slowness, sluggishness, slyness, smallness, smugness, softness, soundness, spiritedness, squeamishness, steadfastness, steepness, sternness, stiffness, stillness, stoutness, strangeness, stubbornness, sturdiness, suddenness, suggestiveness, surfaceness, sweetness, swiftness, tardiness, tartness, tastiness, tenderness, tennis, terseness, tetanus, thickness, thoroughness, ticinus, tightness, timeliness, titinus, togetherness, toughness, trustworthiness, truthfulness, ugliness, uneasiness, unfairness, uniqueness, unpleasantness, unwieldiness, uranus, urness, usefulness, vaness, vanous, vastness, venice, venous, venus, villainous, vincennes, vindictiveness, vividness, voluminous, wastefulness, waterishness, weakness, weariness, weightlessness, weirdness, wellness, wetness, whiteness, wholesomeness, wickedness, wilderness, wildness, willingness, wimpiness, wistfulness, witness, witness', wonderfulness, worldliness, wryness, yanis
Smoothness sounds like:
sanding, sandino's, sandness, scantiness, sending, sentence, sentences, shandong, shantytowns, shunting, smeeting, smoothens, smoothing, something, something's, somethings, sometimes, sondheim's, sounding, soundings, soundness, squinting, sumitomo's, summations, sundance