Or search: os, bone, tusk, ivory, tooth, dentin
2 Syllables: SU
20, any, Bentley, benzene, demi, densely, emptied, empties, empty, entries, entry, envied, envy, frenzied, frenzy, friendly, gently, gentry, Henley, Henri, Henry, Henry's, Jenny, lengthy, many, pennies, penny, plenty, semi, sentries, sentry, twenties, twenty, Wednesday
3 Syllables: SUU
differently
3 Syllables: USU
antennae, assemblies, assembly, excellencies, Excellency, immensely, intensely, intently, Mackenzie, unfriendly, Viennese
4 Syllables: UUSU
complementary, elementary, incidentally, unpretending

Found 50 words across 4 groupings.