moving or situated in the opposite direction from that in which a stream or river flows; nearer to the source 逆流而上(的),在(往)上游(的) [as adv.]a lone motor cruiser rumbled upstream. 一艘摩托游艇隆隆地逆流而上。 [as adj.]the upstream stretch of the Nene. 尼恩河的上游段。 ■(Biology)situated in or towards the part of a sequence of genetic material where transcription takes place earlier than at a given point (生)(基因序列)上游的 ■at a stage in the process of gas or oil extraction and production before the raw material is ready for refining (炼油等过程)上游的,上流的