Or search: folk, sept, linage, stemma, descent, kinship, phratry, pedigree, purebred, genealogy, filiation, derivation, extraction, inheritance
2 Syllables: SU
dimness, England's, grimace, idioms, image, inches, incomes, Indians, India's, Indus, interests, kingdoms, Lincoln's, linkage, minions, myriads, periods, pinions, Plymouth, princes, Scythians, simplest, sinless, sinuous, spinach, symptoms, Syrians
3 Syllables: USU
Assyrians, Corinthians, distinctions, distinctness, dominions, Olympus, opinions, Parisians
4 Syllables: UUSU
ignominious, Presbyterians

Found 37 words across 3 groupings. Skipped 1 excess word of a similar stem.