Downriver (adverb)

1. In the direction that the current of a river flows.
2. Along or near the course of a river.
3. Toward the mouth of a river.

Origin:

From down + river.

Examples:

1. The canoe drifted downriver with the current.
2. We hiked downriver to the next village.
3. The barge is traveling downriver to the port.
4. Fishermen caught a lot of salmon downriver from the dam.
5. The pollution is spreading downriver and affecting wildlife.