Answer:

peepholes

Answer	Crossword Clue
PEEPHOLES	Apartment security devices
PEEPHOLES	Openings for spies
PEEPHOLES	Spying apertures

PEEPHOLES	Door features
PEEPHOLES	Viewpoints?
PEEPHOLES	Spy rings?
PEEPHOLES	Features of most hotel doors

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.