Driftweed

Part of speech: noun

Definitions

1. Seaweed that floats on the surface of the ocean, moved along by the currents
2. Marine plants that are carried by water flows across the sea surface
3. Algae or similar aquatic vegetation that drifts on ocean waters with the currents

Etymology: "Driftweed" is a plain compound: "drift" joined to "weed." "Drift" comes from the Old Norse "drift," meaning something driven along, and in English it came to name whatever is carried by currents or wind. "Weed" in this sense is the older English word for a plant, especially one growing where it is not wanted, and it has long been used for seaweed along the coast. Put together, the word describes the seaweed that floats free on the open water instead of clinging to rocks on the shore, carried along by the same currents that move the sea. The image is literal: a tangle of weed that has been driven off its anchorage and now goes wherever the water takes it.