moss
n. C / U B2 Upper Intermediate US //ˈmɔs// UK //mˈɒs// moss
n. a small, soft green plant that grows in thick mats on damp ground, rocks, or trees. It does not have flowers or seeds and loves shady places.
n. a small, non-vascular flowerless plant in the division Bryophyta, typically growing in dense green clumps or mats in damp or shady locations.
Green moss grows on the north side of the old stone wall.
The forest floor was covered in a thick carpet of moss that felt like a sponge under our feet.
Ecologists monitor the growth of specific moss species as bioindicators of air quality and moisture levels within ancient woodland ecosystems.
Usage
Uncountable when referring to the plant mass generally; countable when referring to specific biological species or varieties.