mousehole

Short definition from Wiktionary

Noun

1. 1
   A hole through which a mouse enters a room.
2. 2
   Any small hole or opening.
3. 3
   The storage area on a drilling rig where the next joint of drilling pipe is held until needed.

Proper noun

1. 1
   A village and fishing port in Penzance parish, Cornwall, England (OS grid ref SW4726).