1. In a manner relating to or using a periscope; by means of a periscope or periscopic vision.
Usage: technical; chiefly nautical and military
2. In a way that allows vision around or over obstacles; with a wide or indirect field of view.
Usage: figurative

Examples

• The submarine captain periscopically surveyed the harbor before surfacing.
• The security system monitored the area periscopically using angled mirrors.
• He periscopically observed the crowd from behind the partition.
• The device allowed operators to view the interior periscopically without direct access.
• Soldiers periscopically scanned the terrain from their fortified position.