Sleepiness rhymes with:
happiness, sloppiness, wimpiness, airworthiness, arbitrariness, bagginess, bitchiness, bounciness, clumsiness, cockiness, contrariness, coziness, craziness, creditworthiness, deadliness, dizziness, dreariness, drowsiness, edginess, emptiness, funniness, ghastliness, hairiness, happiness, healthiness, holiness, laziness, liveliness, loneliness, lousiness, nastiness, niggardliness, nosiness, orderliness, pettiness, queasiness, raciness, readiness, riskiness, roominess, rowdiness, scantiness, sexiness, shakiness, silliness, sloppiness, slovenliness, sturdiness, tardiness, tastiness, timeliness, trustworthiness, ugliness, uneasiness, unwieldiness, weariness, wimpiness, worldliness
Sleepiness sounds like:
scalping, shelving, slapping, slavens, slavinski, sleeping, slip-ons, slipping, slivinski, sloping, sloppiness, slovenes, solvency, solving, sullivan's, sullivans, sylvanus