grass
n. C / U A2 Elementary Oxford US //ˈɡɹæs// UK //ɡɹˈɑːs// grass
n. the common green plant with thin leaves that covers the ground in parks and gardens.
n. vegetation consisting of short plants with long, narrow leaves, belonging to the family Poaceae. Often used collectively to describe a lawn or pasture.
The children are playing on the green grass.
The gardener spent the entire afternoon cutting the grass to keep the lawn looking neat.
Cattle grazed peacefully on the lush grass that covered the rolling hills of the countryside during the height of summer.
Usage
Uncountable when referring to the plant as a mass; countable when referring to specific botanical species.