Or search: kit, rig, gear, tack, tackle, fitting, fixings, regalia, rigging, saddlery, accessory, component, equipment, trimmings, supplement
3 Syllables: SUU
Clarendon, firmament
4 Syllables: USUU
experiment, impertinence

Found 4 words across 2 groupings. Skipped 1 excess word of a similar stem.