A form of viewing device that allows the viewer to see things at a different height level and usually with minimal visibility.
1918, Edgar Rice Burroughs, The Land That Time Forgot (novel) Chapter IVThe waters grew suddenly lighter, and my spirits rose accordingly. I shouted down to those below that I saw daylight ahead, and a great shout of thanksgiving reverberated through the ship. A moment later we emerged into sunlit water, and immediately I raised the periscope and looked about me upon the strangest landscape I had ever seen.
(obsolete): A general or comprehensive view.
1885, ... will show it not only enlarging the periscope of knowledge, but contributing to the amelioration of the condition of unfortunate and suffering humanity ...
(intransitive) To rise and peer around, in the manner of a periscope.
1951, National Geographic Magazine: Volume 99,Thousands of ungainly black-beaked heads would periscope and freeze in the direction of the approaching intruder.
1987, Field & Stream March 1987,The second summer I had a great deal of interest but weeks passed before I worked up the nerve to approach her, the confidence finally gained when I caught a queen snake that periscoped within reach, one of the last I ever saw swimming in Cross Creek.
2008, Doug Stamm, The Springs of Florida page 99Areas of barren sand are likely spots to look for its turtle'speriscoping head. Its fondness for the bottom is equally matched by its ability to quickly disappear and tunnel into it.
2010, Jim Moran, The Sentinel: A Wildfire Story page 236Her black and white head suddenly popped out from under the covers and periscoped around.
