English Reference

Word

periscope

US/ˈpɛɹəˌskoʊp/

UK/pˈɛɹɪskˌəʊp/

Definition

n. a tool that lets you see around a corner or over a wall. It is made of two mirrors that reflect light so you can see things that are hidden from your view.

n. an optical instrument consisting of a pair of mirrors set at an angle to each other, allowing the viewer to see around corners or over obstacles. Often used in military contexts or for simple observation in tight spaces.

Examples

“He used a periscope to look around the corner of the building.”

“The soldiers used a periscope to observe the enemy camp without exposing themselves to direct fire.”

“In the absence of modern surveillance technology, the periscope served as a vital tool for reconnaissance, providing a clear line of sight through narrow alleyways and high walls.”

Examples

simple

“He used a periscope to look around the corner of the building.”

contextual

“The soldiers used a periscope to observe the enemy camp without exposing themselves to direct fire.”

complex

“In the absence of modern surveillance technology, the periscope served as a vital tool for reconnaissance, providing a clear line of sight through narrow alleyways and high walls.”

Real-World Examples

“The roost functions as an equally eccentric character in itself, filled with contraptions, dark wooden furniture and a periscope to nervously keep an eye on the world outside.”
The Guardian · 27 Aug 2026

Etymology

Formed in English from peri- + -scope.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domain

Internet

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

englishreference.com/q/periscope

English Reference