The Collaborative International Dictionary of English v.0.48:

Lodger \Lodg"er\, n.
   One who, or that which, lodges; one who occupies a hired room
   in another's house.
   [1913 Webster]

WordNet (r) 3.0 (2006):

lodger
    n 1: a tenant in someone's house [syn: lodger, boarder,
         roomer]

The Devil's Dictionary (1881-1906):

LODGER, n.  A less popular name for the Second Person of that
delectable newspaper Trinity, the Roomer, the Bedder, and the Mealer.