verb · to build an additional story or extension onto an existing building

他在旧房子的楼顶加盖了一间阁楼。

verb · to put a lid or cap on a container, such as a cooking pot

水烧开后，加盖焖五分钟。

verb · to seal or stamp a document with an official mark, often to ratify or authorize it

请在合同末页加盖公章。