1. (

• unforgiving

) unwilling or unable to forgive or show mercy; "a surly unforgiving old woman" ;

2. (

• grim ,
• inexorable ,
• relentless ,
• stern ,
• unappeasable ,
• unforgiving ,
• unrelenting

) not to be placated or appeased or moved by entreaty; "grim determination"; "grim necessity"; "Russia's final hour, it seemed, approached with inexorable certainty"; "relentless persecution"; "the stern demands of parenthood" ;