The Collaborative International Dictionary of English v.0.48:

Learn \Learn\ (l[~e]rn), v. t. [imp. & p. p. Learned
   (l[~e]rnd), or Learnt (l[~e]rnt); p. pr. & vb. n.
   Learning.] [OE. lernen, leornen, AS. leornian; akin to OS.
   lin[=o]n, for lirn[=o]n, OHG. lirn[=e]n, lern[=e]n, G.
   lernen, fr. the root of AS. l[=ae]ran to teach, OS.
   l[=e]rian, OHG. l[=e]ran, G. lehren, Goth. laisjan, also Goth
   lais I know, leis acquainted (in comp.); all prob. from a
   root meaning, to go, go over, and hence, to learn; cf. AS.
   leoran to go. Cf. Last a mold of the foot, lore.]
   1. To gain knowledge or information of; to ascertain by
      inquiry, study, or investigation; to receive instruction
      concerning; to fix in the mind; to acquire understanding
      of, or skill; as, to learn the way; to learn a lesson; to
      learn dancing; to learn to skate; to learn the violin; to
      learn the truth about something. "Learn to do well." --Is.
      i. 17.
      [1913 Webster]

            Now learn a parable of the fig tree.  --Matt. xxiv.
                                                  32.
      [1913 Webster]

   2. To communicate knowledge to; to teach. [Obs.]
      [1913 Webster]

            Hast thou not learned me how
            To make perfumes ?                    --Shak.
      [1913 Webster]

   Note: Learn formerly had also the sense of teach, in
         accordance with the analogy of the French and other
         languages, and hence we find it with this sense in
         Shakespeare, Spenser, and other old writers. This usage
         has now passed away. To learn is to receive
         instruction, and to teach is to give instruction. He
         who is taught learns, not he who teaches.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Learn \Learn\, v. i.
   To acquire knowledge or skill; to make progress in acquiring
   knowledge or skill; to receive information or instruction;
   as, this child learns quickly.
   [1913 Webster]

         Take my yoke upon you and learn of me.   --Matt. xi.
                                                  29.
   [1913 Webster]

   To learn by heart. See By heart, under Heart.

   To learn by rote, to memorize by repetition without
      exercise of the understanding.
      [1913 Webster]

WordNet (r) 3.0 (2006):

learn
    v 1: gain knowledge or skills; "She learned dancing from her
         sister"; "I learned Sanskrit"; "Children acquire language
         at an amazing rate" [syn: learn, larn, acquire]
    2: get to know or become aware of, usually accidentally; "I
       learned that she has two grown-up children"; "I see that you
       have been promoted" [syn: learn, hear, get word, get
       wind, pick up, find out, get a line, discover,
       see]
    3: commit to memory; learn by heart; "Have you memorized your
       lines for the play yet?" [syn: memorize, memorise, con,
       learn]
    4: be a student of a certain subject; "She is reading for the
       bar exam" [syn: learn, study, read, take]
    5: impart skills or knowledge to; "I taught them French"; "He
       instructed me in building a boat" [syn: teach, learn,
       instruct]
    6: find out, learn, or determine with certainty, usually by
       making an inquiry or other effort; "I want to see whether she
       speaks French"; "See whether it works"; "find out if he
       speaks Russian"; "Check whether the train leaves on time"
       [syn: determine, check, find out, see, ascertain,
       watch, learn]

Moby Thesaurus II by Grady Ward, 1.0:

77 Moby Thesaurus words for "learn":
   absorb, appreciate, apprehend, ascertain, assimilate,
   attend classes, attend school, awaken to, be informed, be with one,
   become acquainted with, become alive to, become aware of,
   become conscious of, broaden the mind, catch, catch on,
   chance upon, come to know, commit to memory, comprehend, conceive,
   cram the mind, determine, dig, digest, discover, fathom, find,
   find out, find out about, follow, gain knowledge, gather, get,
   get hep to, get hold of, get it, get next to, get the drift,
   get the idea, get the picture, get wise to, go into training,
   go to school, grasp, have, have it reported, have it taped,
   hear of, hit upon, ken, know, learn about, learn by heart,
   load the mind, master, memorize, pick up information, read,
   read with, realize, receive instruction, savvy, see the light,
   seize, seize the meaning, sense, serve an apprenticeship, take,
   take in, take lessons, train, twig, uncover, undergo schooling,
   understand