1. superlative form of grim; most forbidding, harsh, or unpleasant in appearance or manner
Usage: superlative form
2. most serious or worrying; most dire or alarming
Usage: superlative form

Examples

• The grimmest predictions about the economy proved to be accurate.
• He wore the grimmest expression I had ever seen on his face.
• This was the grimmest winter in decades, with record-breaking cold.
• The doctor delivered the grimmest news about her condition.
• Even in the grimmest circumstances, she maintained her sense of humor.
• The grimmest part of the journey lay ahead of them.