The Collaborative International Dictionary of English v.0.48:

Facet \Fac"et\, n. [F. facette, dim. of face face. See Face.]
   1. A little face; a small, plane surface; as, the facets of a
      diamond. [Written also facette.]
      [1913 Webster]

   2. (Anat.) A smooth circumscribed surface; as, the articular
      facet of a bone.
      [1913 Webster]

   3. (Arch.) The narrow plane surface between flutings of a
      column.
      [1913 Webster]

   4. (Zool.) One of the numerous small eyes which make up the
      compound eyes of insects and crustaceans.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Facet \Fac"et\, v. t. [imp. & p. p. Faceted; p. pr. & vb. n.
   Faceting.]
   To cut facets or small faces upon; as, to facet a diamond.
   [1913 Webster]

WordNet (r) 3.0 (2006):

facet
    n 1: a distinct feature or element in a problem; "he studied
         every facet of the question" [syn: aspect, facet]
    2: a smooth surface (as of a bone or cut gemstone)

Moby Thesaurus II by Grady Ward, 1.0:

116 Moby Thesaurus words for "facet":
   angle, anteriority, article, aspect, bold front, border,
   brave face, brave front, case, circumference, configuration,
   cortex, count, covering, crust, datum, detail, display, effect,
   eidolon, element, envelope, epidermis, exterior, external, facade,
   face, facia, fact, factor, fashion, feature, figure, fore,
   forefront, foreground, forehand, foreland, forepart, forequarter,
   foreside, foreword, form, fringe, front, front elevation,
   front man, front matter, front page, front view, frontage, frontal,
   frontier, frontispiece, gestalt, guise, hand, head, heading, image,
   imago, impression, incidental, instance, integument, item, lap,
   light, likeness, lineaments, look, manner, matter, minor detail,
   minutia, minutiae, obverse, outer face, outer layer, outer side,
   outer skin, outline, outside, particular, periphery, phase, phasis,
   point, preface, prefix, priority, proscenium, reference, regard,
   respect, rind, seeming, semblance, shape, shell, side, simulacrum,
   skin, slant, style, superficies, superstratum, surface, thing, top,
   total effect, twist, view, viewpoint, window dressing, wise