The Collaborative International Dictionary of English v.0.48:

Rim \Rim\, n. [As. rima, reoma, edge; cf. W. rhim, rhimp, a rim,
   edge, boundary, termination, Armor, rim. Cf. Rind.]
   1. The border, edge, or margin of a thing, usually of
      something circular or curving; as, the rim of a kettle or
      basin.
      [1913 Webster]

   2. The lower part of the abdomen. [Obs.] --Shak.
      [1913 Webster]

   Arch rim (Phonetics), the line between the gums and the
      palate.

   Rim-fire cartridge. (Mil.) See under Cartridge.

   Rim lock. See under Lock.
      [1913 Webster]