Or search: bode, omen, augur, bespeak, portend, predict, presage, betoken, forecast, foretell, threaten, foreshow, auspicate, prefigure, prognosticate
2 Syllables: SU
backbone, Blackstone, cathode, facto, Gladstone, hallowed, macro, shadow
3 Syllables: USU
tobacco, unhallowed
4 Syllables: UUSU
Colorado, overshadow

Found 12 words across 3 groupings. Skipped 3 excess words of a similar stem.