1. grass; weed; herb; thatch
そして、草が目の前に見えた。And then, grass appeared before my eyes.
2. ninja
3. marijuana; cannabis
4. not genuine; substandard
5. LOL; haha
from multiple repetitions of "w" ("LOL") resembling grass: wwwwww
また同じミスしてて草。LOL, made the same mistake again.