to lay the main upper beam of a building, often as part of a construction ceremony

按照习俗，新房上梁要燃放鞭炮以示庆贺。

verb · the upper horizontal tube of a bicycle frame

这辆山地车的上梁非常坚固。

the top or main horizontal beam of a building structure

上梁不正下梁歪，作为领导必须以身作则。