an optical instrument for viewing objects that are above the level of direct sight or in an otherwise obstructed field of vision, consisting essentially of a tube with an arrangement of prisms or mirrors and, usually, lenses: used especially in submarines.
a periscopic lens.
Origin of periscope
First recorded in 1815–25;
back formation from periscopic
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for periscope
Historical Examples of periscope
The conning-tower and periscope are placed on the upper deck, as shown.
I was glad when I picked up its homely white front in my periscope.
The captain turns the periscope around, scanning the waters.
He looked neither to right nor left but was still at the periscope.
This periscope was not in use and had not been above the surface.
British Dictionary definitions for periscope
any of a number of optical instruments that enable the user to view objects that are not in the direct line of vision, such as one in a submarine for looking above the surface of the water. They have a system of mirrors or prisms to reflect the light and often contain focusing lenses
Word Origin for periscope
C19: from Greek periskopein to look around; see peri-, -scope
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for periscope
viewing apparatus on a submarine, 1899, formed in English from peri- "around" + -scope "instrument for viewing." Earlier (1865) a technical term in photography. Related: Periscopic.
Online Etymology Dictionary, © 2010 Douglas Harper
An instrument that has angled mirrors or prisms and allows objects not in the direct line of sight to be seen, often used on submarines and in military reconnaissance.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.