The Collaborative International Dictionary of English v.0.48:

Scan \Scan\ (sk[a^]n), v. t. [imp. & p. p. Scanned (sk[a^]nd);
   p. pr. & vb. n. Scanning.] [L. scandere, scansum, to climb,
   to scan, akin to Skr. skand to spring, leap: cf. F. scander.
   Cf. Ascend, Descend, Scale a ladder.]
   1. To mount by steps; to go through with step by step. [Obs.]
      [1913 Webster]

            Nor stayed till she the highest stage had scand.
                                                  --Spenser.
      [1913 Webster]
      [1913 Webster]

   2. Specifically (Pros.), to go through with, as a verse,
      marking and distinguishing the feet of which it is
      composed; to show, in reading, the metrical structure of;
      to recite metrically.
      [1913 Webster]

   3. To go over and examine point by point; to examine with
      care; to look closely at or into; to scrutinize.
      [1913 Webster]

            The actions of men in high stations are all
            conspicuous, and liable to be scanned and sifted.
                                                  --Atterbury.
      [1913 Webster]

   4. To examine quickly, from point to point, in search of
      something specific; as, to scan an article for mention of
      a particular person.
      [PJC]

   5. (Electronics) To form an image or an electronic
      representation of, by passing a beam of light or electrons
      over, and detecting and recording the reflected or
      transmitted signal.
      [PJC]

WordNet (r) 3.0 (2006):

scanning
    n 1: the process of translating photographs into a digital form
         that can be recognized by a computer
    2: the act of systematically moving a finely focused beam of
       light or electrons over a surface in order to produce an
       image of it for analysis or transmission

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "scanning":
   EDP, Stabreim, alliterative meter, analyzing, antispastic,
   automatic tracking, cadenced, classifying, collating,
   computer technology, computer typesetting, computing, dactylic,
   data processing, data retrieval, data transmission,
   electronic data processing, flector tuning,
   high-speed data handling, iambic, interlaced scanning, locking on,
   locking signals, machine computation, mapping, measure, measured,
   meter, metric, metrical pattern, metrics, mixing, monitoring,
   numbers, phase adjustment, pinpointing, precision focusing,
   prosodic, prosodic pattern, prosody, pyrrhic, quantitative meter,
   radar navigation, radar-telephone relay, range finding, reporting,
   rhythmic, scan conversion, scansion, shading, signal modulation,
   sorting, spondaic, switching, syllabic meter, telecasting,
   televising, three-pointing, tracking, triangulation,
   triggering signals, trochaic, vers libre, versification