1. (adjective) not to be placated or appeased or moved by entreaty

• grim
• inexorable
• relentless
• stern
• unappeasable
• unrelenting

1. (adjective) unwilling or unable to forgive or show mercy

• revengeful
• vengeful
• vindictive

2. (adjective) not to be placated or appeased or moved by entreaty

• implacable

1. (adjective) not to be placated or appeased or moved by entreaty

• asperity
• grimness
• hardship
• rigor
• rigorousness
• rigour
• rigourousness
• severeness
• severity
• inexorability
• inexorability
• inexorability
• inexorableness
• inexorableness
• inexorableness
• relentlessness
• relentlessness
• relentlessness
• sternness
• strictness

1. (adjective) unwilling or unable to forgive or show mercy

• forgiving