Mulch (noun)

1. A layer of material, such as dead leaves or grass, spread over the surface of the soil to reduce evaporation, prevent erosion, and suppress weeds.
2. A material, such as bark or compost, spread over the surface of soil around plants to retain moisture and suppress weeds.

Origin:

Mid 17th century: probably from old norse mulr "soft, tender".

Examples:

1. He spread a layer of mulch around the trees.
2. She put mulch on the flower bed to keep the moisture.
3. The mulch helped to keep the soil cool and moist.
4. The mulch was made of leaves and twigs.
5. The mulch helped to suppress the growth of weeds.