peephole
noun
- glass opening in door
Wiktionary
Pronunciation: /ˈpiːphəʊl/ / /ˈpiːphoʊl/ / [ˈpʰiːphoʊɫ]
noun
Etymology: From peep + hole.
- A small hole, opening, or piece of glass, especially in a door, through which one can look without being seen.
“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.”