periscope

/ˈpɛrɪskoʊp/
noun
  1. A tube with mirrors or prisms that allows someone to see over or around an obstacle, especially used in submarines to see above the water.
    • The submarine captain raised the periscope to check for enemy ships.
    • The soldier used a periscope to look over the trench without exposing his head.
    • During the science fair, the student built a simple periscope using cardboard and mirrors.
Synonyms
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