2 Syllables: SU
bringeth, dimness, English, finis, finish, Finnish, fringes, glimpses, grimace, hinges, igneous, image, inches, India's, Indus, influx, ingots, kingship, kinship, lineage, linguist, linkage, pinkish, Plymouth, princes, ringlets, shrinkage, simplest, sinless, sinuous, spinach, thinness, thinnest, trinkets, vintage, Winthrop
3 Syllables: SUU
fingertips, impetus, incubus, infamous, infinite, interdict, intimate, intricate, simulate, singleness, stimulus, synchronous, synthesis, timorous
3 Syllables: USU
convinces, diminish, distinctive, distinctness, distinguish, evinces, extinguish, extrinsic, incentives, instinctive, intrinsic, Olympic, Olympus, relinquish, unfinished
4 Syllables: UUSU
Found 68 words across 4 groupings. Skipped 6 excess words of a similar stem.