1. the quality of being solid, hard, or stable; not soft or yielding
2. strength of character; determination and resolve
3. strictness or severity in manner or approach

Examples

• The firmness of the mattress provided good back support.
• She tested the firmness of the fruit before buying it.
• His firmness in negotiations helped secure a better deal.
• The teacher’s firmness maintained order in the classroom.
• The coach showed firmness when enforcing team rules.
• The firmness of her handshake impressed the interviewer.
• Parents need to balance kindness with firmness when disciplining children.