幹事【かんじ】
executive secretary, coordinator, organizer, person in charge of making arrangements
幹部【かんぶ】
management, (executive) staff, leaders, leadership, top brass, upper echelons
新幹線【しんかんせん】
Shinkansen, bullet train
幹【みき】
(tree) trunk, (arrow) shaft, (tool) handle, backbone, base
根幹【こんかん】
foundation, root, basis, core, fundamentals, root and trunk