Definition:

A spyhole is a small opening or peephole designed to provide a discreet view of an area without being noticed.

Noun

Sense 1:

A hole or opening, often fitted with a lens, through which one can secretly observe a room, passage, or other enclosed space.

Example Sentence:

She discreetly peeked through the spyhole to see who was at the door before opening it.

Verb

Sense 1:

To secretly observe or watch someone or something.

Example Sentence:

The detective skillfully spyholed the suspect to gather evidence.

Adjective

Sense 1:

Referring to something being secretive or stealthy.

Example Sentence:

The thief made a spyhole entrance to avoid detection by the security cameras.