Or search: exogamic, exogamous, anthropology
1 Syllable: S
bout, bowed, cloud, clout, cowed, crowd, doubt, dour, dower, drought, flour, gout, hour, loud, our, out, ploughed, plowed, proud, rout, route, scour, scout, shout, shroud, snout, sour, sowed, spout, sprout, stout, tout, trout, vowed
2 Syllables: US
about, allowed, aloud, avowed, devout, endowed, Macleod, redoubt, throughout, without
3 Syllables: UUS
disallowed, disavowed, thereabouts

Found 47 words across 3 groupings. Skipped 14 excess words of a similar stem.