1. (noun) any of several eruptive skin diseases characterized by hard thick lesions grouped together and resembling lichens growing on rocks

• lichen planus
• lichen ruber planus

2. (noun) any thallophytic plant of the division Lichenes; occur as crusty patches or bushy growths on tree trunks or rocks or bare ground etc.

• arctic moss
• cladonia rangiferina
• reindeer lichen
• reindeer moss
• ascolichen
• basidiolichen
• beard lichen
• beard moss
• usnea barbata
• cetraria islandica
• iceland lichen
• iceland moss
• crotal
• crottal
• crottle
• horsehair lichen
• horsetail lichen
• lecanora
• roccella
• roccella tinctoria

1. (noun) any of several eruptive skin diseases characterized by hard thick lesions grouped together and resembling lichens growing on rocks

• disease of the skin
• skin disease
• skin disorder

2. (noun) any thallophytic plant of the division Lichenes; occur as crusty patches or bushy growths on tree trunks or rocks or bare ground etc.

• fungus

1. (noun) any thallophytic plant of the division Lichenes; occur as crusty patches or bushy growths on tree trunks or rocks or bare ground etc.

• division lichenes
• lichenes