1. A dark substance (typically grease or cream) applied under the eyes to reduce glare and improve visibility, commonly used by athletes in outdoor sports.
Usage: Usually used in plural or as a mass noun; Common in baseball, football, and other outdoor sports

Examples

• The baseball player applied eyeblacks under his eyes before taking the field.
• Football players wear eyeblacks to cut down on sun glare during daytime games.
• She wiped the eyeblacks from her cheeks after the game ended.
• Eyeblacks have been used by athletes for decades to improve their performance in bright conditions.
• The coach reminded the team to apply their eyeblacks before the outdoor match.