1. small holes or openings through which one can look secretly or observe without being seen

Examples

• The apartment door had a peephole so residents could see who was visiting.
• Security guards monitored the area through peepholes in the wall.
• She drilled small peepholes in the fence to watch the neighbors.
• The old castle had peepholes built into the stone walls for defense.
• Parents sometimes use peepholes to check on their children without disturbing them.
• The detective discovered peepholes that had been used for surveillance.