Meaning of grave in English

Noun

1. a hole in the ground where a dead body is buried

We put flowers on the grave.

grave²

Adjective

1. very serious, not smiling; solemn

in a grave tone
a grave quiet man
Her face looked grave as she told us about the accident.

2. very serious, needing much attention; crucial

This is grave news.
He is in grave danger.
He made a grave blunder.