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]

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "lodger":
   board-and-roomer, boarder, hirer, homesteader, incumbent,
   leaseholder, lessee, occupant, occupier, paying guest, renter,
   resident, roomer, squatter, sublessee, subtenant, tenant,
   tenant at sufferance, tenant for life, transient, transient guest,
   underlessee



Bouvier's Law Dictionary, Revised 6th Ed (1856):

LODGER. One who has a right to inhabit another man's house. He has not the
same right as a tenant; and is not entitled to the same notice to quit.
Woodf. L. &_T. 177. See 7 Mann. & Gr. 87; S. C. 49 E. C. L. R. 85, 151, and
article Inmate.



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.