Definitions:
in the opposite direction from that in which a stream or river flows; nearer to the source

in or towards the part of a sequence of genetic material where transcription takes place earlier than at a given point.

at a stage in the process of gas or oil extraction and production before the raw material is ready for refining.

moving or situated in the opposite direction from that in which a stream or river flows

situated in or towards the part of a sequence of genetic material where transcription takes place earlier than at a given point.

relating to the stages in the process of gas or oil extraction and production before the raw material is ready for refining.