D defs.my
Entry 1 sense Webster, 1913

Plankton

/(plăṉk"tŏn)/ · Plank·ton · IPA /ˈplæŋ(k).tən/
01 n. All the animals and plants, taken collectively, which live at or near the surface of salt or fresh waters.
  1. 1.
    All the animals and plants, taken collectively, which live at or near the surface of salt or fresh waters.(Biol.)