The Collaborative International Dictionary of English v.0.48:

Comprehend \Com`pre*hend"\, v. t. [imp. & p. p. Comprehended;
   p. pr. & vb. n. Comprehending.] [L. comprehendere,
   comprehensum; com- + prehendere to grasp, seize; prae before
   + hendere (used only in comp.). See Get, and cf.
   Comprise.]
   1. To contain; to embrace; to include; as, the states
      comprehended in the Austrian Empire.
      [1913 Webster]

            Who hath . . . comprehended the dust of the earth in
            a measure.                            --Is. xl. 12.
      [1913 Webster]

   2. To take in or include by construction or implication; to
      comprise; to imply.
      [1913 Webster]

            Comprehended all in this one word, Discretion.
                                                  --Hobbes.
      [1913 Webster]

            And if there be any other commandment, it is briefly
            comprehended in this saying.          --Rom. xiii.
                                                  9.
      [1913 Webster]

   3. To take into the mind; to grasp with the understanding; to
      apprehend the meaning of; to understand.
      [1913 Webster]

            At a loss to comprehend the question. --W. Irwing.
      [1913 Webster]

            Great things doeth he, which we can not comprehend.
                                                  --Job. xxxvii.
                                                  5.

   Syn: To contain; include; embrace; comprise; inclose; grasp;
        embody; involve; imply; apprehend; imagine; conceive;
        understand. See Apprehend.
        [1913 Webster]

WordNet (r) 3.0 (2006):

comprehend
    v 1: get the meaning of something; "Do you comprehend the
         meaning of this letter?" [syn: grok, get the picture,
         comprehend, savvy, dig, grasp, compass,
         apprehend]
    2: to become aware of through the senses; "I could perceive the
       ship coming over the horizon" [syn: perceive, comprehend]
    3: include in scope; include as part of something broader; have
       as one's sphere or territory; "This group encompasses a wide
       range of people from different backgrounds"; "this should
       cover everyone in the group" [syn: embrace, encompass,
       comprehend, cover]

Moby Thesaurus II by Grady Ward, 1.0:

86 Moby Thesaurus words for "comprehend":
   absorb, accept, admit, appreciate, apprehend, assimilate,
   be acquainted with, be apprised of, be aware of, be cognizant of,
   be conscious of, be conversant with, be informed, be with one,
   catch, catch on, cognize, compass, complete, comprise, conceive,
   conceptualize, contain, count in, cover, dig, digest, discern,
   embody, embrace, encircle, enclose, encompass, envisage, envision,
   fathom, fill, fill in, fill out, follow, get, get hold of,
   get the drift, get the idea, get the picture, grasp, have,
   have information about, have it taped, have knowledge of, hold,
   include, incorporate, involve, ken, know, learn, make out, master,
   number among, occupy, perceive, possess, prehend, read, realize,
   receive, reckon among, reckon in, reckon with, recognize, savvy,
   see, seize, seize the meaning, sense, subsume, take, take in,
   take into account, take into consideration, take up, twig,
   understand, wot, wot of