n. A vertical pillar along the inner septal margin of a coral.
n. A small plain (compared to mare) on the surface of a planet or satellite.
the GNU version of the Collaborative International Dictionary of English
n. One of several upright slender calcareous processes which surround the central part of the calicle of certain corals.
The Century Dictionary and Cyclopedia
n. In corals, one of the laminæ or plate-like processes which extend upward from the bottom of a coralite to the calice; an extension from the inner edge of certain septa to or toward the columellar space or axis of the visceral chamber.
Word Usage
"Then came the origin of the word pool -- from "palus," a marsh, as we were told, some dictionary attesting to the fact, and such a marsh might cover a large expanse."