Lichen
/ˈlaɪ.kən/noun
A composite organism formed by a fungus living with algae or cyanobacteria, or a crusty, leaflike growth on rocks and trees.
Did you know?The word ultimately traces back to Greek *leikhēn*, used for a kind of skin eruption or blotch, which is why the term was applied to these rough, spreading growths.
Etymological Timeline
Ancient Greek
Greek
λείχην (leikhēn)
“A skin eruption, blotch, or scaly rash.”
Late Latin
Latin
lichen
“A lichen or similar crusty growth.”
Middle French
French
lichen
“Lichen.”
16th Century
English
lichen
“A crusty plantlike growth on rocks, trees, or soil.”
Modern English
English
lichen
“A symbiotic fungus-and-alga organism or its growth form.”