1.
grass
Plants with narrow leaves growing from the base.
2.
weed
Unwanted plants growing in gardens.
3.
herb
Plants used for medicine or flavoring.
草 means grass, weeds, or herbs - general term for small plants.
Common expressions
Compounds
Internet slang
草 or "w" is internet slang for laughter (like "lol"). Multiple "w" (草草草 or www) = lots of laughing. From the Japanese word 笑う (warau, to laugh).
Related Words
Related:
薬草 (medicinal herb)
Related:
草原 (grassland, prairie)
Compare:
芝生 (lawn, grass)