Pronunciation: (noo-mat'u-fôr", -fōr", nyoo-, nOO'mu-tu-, nyOO'-), [key]
1. Bot.a specialized structure developed from the root in certain plants growing in swamps and marshes, serving as a respiratory organ.
2. Zool.the air sac of a siphonophore, serving as a float.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.