Pronunciation: (prō'tu-plaz"um), [key]
1. Biol.(no longer in technical use) the colloidal and liquid substance of which cells are formed, excluding horny, chitinous, and other structural material; the cytoplasm and nucleus.
2. Obs.the living matter of organisms regarded as the physical basis of life, having the ability to sense and conduct stimuli.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.