peephole

English Wikipedia has an article on:

peephole

Wikipedia

View through a peephole

Barack Obama looking through the Oval Office door peephole

From peep +‎ hole.

• (UK) IPA^(key): /piːphəʊl/
• (US) IPA^(key): /piphoʊl/, IPA^(key): [pʰiphoʊɫ]

• Audio (US):

  (file)

• Hyphenation: peep‧hole

peephole (plural peepholes)

1. A small hole, opening, or piece of glass, especially in a door, through which one can look without being seen.
   • 1897, Richard Marsh, The Beetle:

     It’s a conjurer’s den. — I shouldn’t be surprised if cabby’s old gent is staring at us all the while from some peephole of his own.

• spyhole (UK)
• peekhole
• doorhole
• door viewer

• peephole optimization

• knothole, eyehole

• “peephole”, in Collins English Dictionary.
• “peephole”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• “peephole”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “peephole”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.