1 a small flowerless green plant that lacks true roots, growing in lowcarpets or rounded cushions in damp habitats and reproducing by means of spores released from stalked capsules : the trees are overgrown with vines and moss | the bog is home to rare mosses. • Class Musci, divisionBryophyta.• used in names of algae, lichens, and higher plants resembling moss, e.g., reindeer moss, Ceylon moss, Spanish moss.2 Scottish & N. English a bog, esp. a peat bog.
verb [usu. as adj. ] ( mossed)cover with moss.