The Collaborative International Dictionary
Corallum
Corallum \Co*ral"lum\, n. [L.] (Zo["o]l.) The coral or skeleton of a zo["o]phyte, whether calcareous of horny, simple or compound. See Coral.
Wiktionary
corallum
n. (context zoology English) The coral or skeleton of a zoophyte, whether calcareous or horny, simple or compound.