Dictionary
li•chen
Pronunciation: (lī'kun), [key]—
n.
1. any complex organism of the group Lichenes, composed of a fungus in symbiotic union with an alga and having a greenish, gray, yellow, brown, or blackish thallus that grows in leaflike, crustlike, or branching forms on rocks, trees, etc.
2. Pathol.any of various eruptive skin diseases.
—
v.t.
to cover with or as if with lichens.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.