mainstem

Etymology

From main + stem.

mainstem means the principal watercourse of a river that has multiple streams. Lexicurio rates it Sui generis — a strength score of 86 out of 100.

noun

The principal watercourse of a river that has multiple streams“Piramutaba (Brachyplatystoma vaillantii) make up a second large export fishery and are found almost exclusively in the Amazon River mainstem, whitewater tributaries, and the estuary [30 –32 ].”