柯林斯詞典triennial /tra???n??l/ 1. ADJ relating to, lasting for, or occurring every three years 每三年的2. N a third anniversary 三周年紀(jì)念 返回 triennial劍橋詞典happening every three years 每三年的；三年一次的 the association's triennial conference 該協(xié)會(huì)三年一屆的大會(huì) 返回 triennial