Or search: wary, leery, cynical, jealous, doubting, skeptical, sceptical, suspicious, untrusting, incredulous, mistrustful, overjealous, misanthropic, misanthropical, oversuspicious
2 Syllables: SU
Brussels, bustle, cudgel, hovel, hustle, Lovell, muffled, muscle, muzzle, nuptial, puzzle, ruffle, Russel, Russell, Russell's, rustle, scuffle, shovel, shuffle
3 Syllables: USU
industrial, unruffled

Found 21 words across 2 groupings. Skipped 11 excess words of a similar stem.