1. substances or agents that make something black or darker
2. people who damage someone’s reputation or character
Usage: figurative

Examples

• The shoe polish contains blackeners that restore the leather’s dark color.
• Industrial blackeners are used to darken metal surfaces.
• His political opponents were notorious blackeners of his reputation.
• The gossip columnists acted as blackeners, spreading rumors about celebrities.
• Chemical blackeners help create the desired finish on steel products.
• She refused to associate with the blackeners who spread lies about her friend.