noun
undergrowth; weeds beneath trees
Refers to low-growing plants, grass, or weeds under trees or in a forest. Often used in gardening, forestry, or nature descriptions.
庭の下草を刈る。
I cut the undergrowth in the garden.
森の中は下草が生い茂っていた。
The forest was thick with undergrowth.
雑草 refers to weeds in general, often unwanted plants in gardens or fields, while 下草 specifically means low vegetation under trees.
Compound of 下 (した, 'under') and 草 (くさ, 'grass'). The reading したぐさ is a rendaku variant.