Duckweed

Origin

duck + weed

Full definition of duckweed

Noun

1. Any of several reduced floating aquatic plants in the family .
• 1909, H. G. Wells, The Beautiful SuitBut his face was a face of such happiness that, had you seen it, you would have understood indeed how that he had died happy, never knowing that cool and streaming silver for the duckweed in the pond.