from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A gas-filled sac serving as a float in some colonial marine hydrozoans, such as the Portuguese man-of-war.
- n. Botany A specialized respiratory root structure in certain aquatic plants, such as the bald cypress.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A gas-filled sac or float of some colonial marine coelenterates, such as the Portuguese man-of-war.
- n. An aerial root, in mangroves etc., specialized for gaseous exchange.
from the GNU version of the Collaborative International Dictionary of English
- n. One of the Pneumonophora.
from The Century Dictionary and Cyclopedia
- n. A pneumatocyst, or a structure which supports such a float; especially, the proximal dilatation of the cœnosarc or hydrosome of the Physophoridæ See cuts under Athorybia and Hydroszoa.
- n. An apparatus for supplying a person with oxygen when in a place filled with bad or unwholesome air.
- n. In phytogeography, a lateral root, submerged or more often exposed to the air, at least periodically, so differentiated as to serve the purpose of respiration; a respiratory root.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an air-filled root (submerged or exposed) that can function as a respiratory organ of a marsh or swamp plant
pneumato- + -phore (Wiktionary)