Or search: site, brass, plaque, pyramid, memorial, cenotaph, megalith, repository
2 Syllables: SU
conference
3 Syllables: SUU
complement, confident, confluence, Congressman, congruent, consequence, consequent, consonance, consonant, continence, continent, documents, dominance, dominant, monument, prominence, prominent
4 Syllables: USUU
incompetence, incompetent, incontinence, predominance, predominant, preponderant

Found 24 words across 3 groupings. Skipped 3 excess words of a similar stem.