Quick definitions from WordNet (Iceland lichen)
▸ noun: lichen with branched flattened partly erect thallus that grows in mountainous and arctic regions; used as a medicine or food for humans and livestock; a source of glycerol
▸ noun: lichen with branched flattened partly erect thallus that grows in mountainous and arctic regions; used as a medicine or food for humans and livestock; a source of glycerol