from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Plankton that remains free-swimming through all stages of its life cycle.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any organism that spends all of its life-cycle as plankton
from The Century Dictionary and Cyclopedia
- n. The plants and animals that pass their whole life swimming or floating in the water, considered collectively and in contrast with those that float or swim for only a part of their lives, passing the rest upon or in the bottom. See hemibenthic, holebenthic, hemiplankton, holoplanktonic, planktonic.
holo- + plankton (Wiktionary)