dulling

verb

1. To render dull; to remove or blunt an edge or something that was sharp.“Years of misuse have dulled the tools.”
2. To soften, moderate or blunt; to make dull, stupid, or sluggish; to stupefy.“He drinks to dull the pain.”
3. To lose a sharp edge; to become dull.“A razor will dull with use.”
4. To render dim or obscure; to sully; to tarnish.