三通 1.[机械工程] triplet; tee; tee joint; [工业] wye; y; yoke2.(指通邮、通商、通航) “three exchanges”: exchanges of mails, trade, air and shipping services; the opening of postal, aviation and navigational services and commercial interflow◇三通管 three-way pipe; single sweep tee; t-branch (pipe); three-limb tube