noun Download 🔗Share Any of many symbiotic organisms, being associations of algae and fungi, often found as white or yellow patches on old walls, etc. Examples : "The old stone wall had many lichens growing on it, small white and yellow patches. " organism plant biology environment nature ecology Chat with AIVocabulary GamePractice Reading
noun Download 🔗Share Something which gradually spreads across something else, causing damage. Examples : "The dampness in the basement fostered a lichen that slowly spread across the walls, damaging the paint job. " environment biology Chat with AIVocabulary GamePractice Reading