Or search: meal, climax, inspire, straits, ceremony, juncture, landmark, happening, occurrent, ceremonial, jubilation, observance, occurrence, celebration, conjuncture
2 Syllables: SU
hastening, labeling, rationing, straightening
3 Syllables: SUU
catering, favoring, favouring, laboring, labouring, neighboring, neighbouring, tailoring, tapering, wavering
3 Syllables: USU
disabling, enabling
4 Syllables: USUU
awakening, unwavering

Found 18 words across 4 groupings.