Or search: nato, meuse, rhein, rhine, leyden, ijssel, leiden, benelux, holland, utrecht, dutchman, nijmegen, hollander, nederland, friesland
2 Syllables: SU
deference, preference, reference, Reverend
3 Syllables: SUU
betterment, Egerton, Emerson, Jefferson, Jefferson's, measurement, reverence, reverent, severance
4 Syllables: USUU
irreverence, irreverent

Found 15 words across 3 groupings. Skipped 2 excess words of a similar stem.