Pronunciation: (lī'kun), [key]
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.
to cover with or as if with lichens.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.