Or search: autocracy, despotism, dominance, stalinism, caesarism, monocracy, shogunate, ascendance, ascendancy, ascendency, ascendence, totalitarianism, authoritarianism
2 Syllables: SU
histories, theories
3 Syllables: SUU
deities, fisheries, liveries, miseries, mysteries, Philippines, Philistines, Pyrenees, similes, tyranny, vicarage
3 Syllables: USU
deliveries
4 Syllables: USUU
abilities, affinities, antipathies, antipodes, antiquities, civilities, conspiracies, divinities, facilities, festivities, hostilities, proclivities, utilities
5 Syllables: UUSUU
aborigines, capabilities, disabilities, liabilities, possibilities, probabilities
6 Syllables: UUUSUU
impossibilities, responsibilities, susceptibilities

Found 36 words across 6 groupings.