pinhole

Short definition from Wiktionary

Noun

1. 1
   A small hole, of a size that could have been made by a pin
2. 2
   The aperture in a pinhole camera or camera obscura
3. 3
   A port left unprotected by a firewall to allow a particular application to gain access to a service.
4. 4
   A clipping of pinhole eye, which refers to the compact eye structure associated with intense tropical cyclones.

Verb

1. 1
   To form one or more pinholes in.