coralline

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of, consisting of, or producing coral.
• adjective Resembling coral, especially in color.
• noun Any of various red algae of the family Corallinaceae whose fronds are covered with calcareous deposits.
• noun Any of various organisms that resemble coral, such as certain bryozoans.

from The Century Dictionary.

• noun Commercial rosolic acid.
• Consisting of or containing coral; resembling coral; coral. Specifically
• Having a color somewhat resembling that of red coral; red, pinkish-red, or reddish-yellow.
• noun A seaweed with rigid calcareous fronds: so called from its resemblance to coral. See Corallina.
• noun A coral or other zoöphyte or actinozoan: a term extended also to polyzoans or moss-animalcules, and to some of the hydrozoans.
• noun [In this sense commonly corallin.] A dye, prepared commercially by heating together phenol, anhydrous oxalic acid, and oil of vitriol, and producing a very unstable color.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Composed of corallines.
• noun (Bot.) A submarine, semicalcareous or calcareous plant, consisting of many jointed branches.
• noun (Zoöl.) Formerly any slender coral-like animal; -- sometimes applied more particulary to bryozoan corals.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Of, relating to or pertaining to or resembling red algae of the family Corallinaceae.
• adjective Of, pertaining to, or resembling the material coral.
• adjective Describing rock formed from the skeletons of such algae.
• noun Any calcareous species of red algae of the family Corallinaceae.
• noun An animal that resembles such a coral.