Unfilled rhymes with:
filled, fulfilled, refilled, unfulfilled, bild, billed, build, childe, chilled, distilled, drilled, filled, fulfilled, gild, grilled, guild, hild, hilde, instilled, killed, milled, rebuild, refilled, skilled, spilde, spilled, stilled, thrilled, unfulfilled, unskilled, willed
Unfilled sounds like:
umfleet, umphlett, unaffiliate, unaffiliated, unbolt, unbolted, unbuilt, unemployed, unfold, unfolded, unveiled