The Collaborative International Dictionary of English v.0.48:

Betoken \Be*to"ken\, v. t. [imp. & p. p. Betokened; p. pr. &
   vb. n. Betokening.]
   1. To signify by some visible object; to show by signs or
      tokens.
      [1913 Webster]

            A dewy cloud, and in the cloud a bow . . .
            Betokening peace from God, and covenant new.
                                                  --Milton.
      [1913 Webster]

   2. To foreshow by present signs; to indicate something future
      by that which is seen or known; as, a dark cloud often
      betokens a storm.
      [1913 Webster]

   Syn: To presage; portend; indicate; mark; note.
        [1913 Webster]

WordNet (r) 3.0 (2006):

betoken
    v 1: be a signal for or a symptom of; "These symptoms indicate a
         serious illness"; "Her behavior points to a severe
         neurosis"; "The economic indicators signal that the euro is
         undervalued" [syn: bespeak, betoken, indicate,
         point, signal]
    2: indicate by signs; "These signs bode bad news" [syn: bode,
       portend, auspicate, prognosticate, omen, presage,
       betoken, foreshadow, augur, foretell, prefigure,
       forecast, predict]

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "betoken":
   affect, announce, approve, argue, attest, augur, be construed as,
   be indicative of, be significant of, be symptomatic of, bespeak,
   bode, brandish, breathe, bring forth, bring forward,
   bring into view, bring out, bring to notice, characterize, connote,
   dangle, demonstrate, denominate, denote, develop, differentiate,
   disclose, display, divine, divulge, dramatize, embody, enact,
   entail, evidence, evince, exhibit, expose to view, express, flaunt,
   flourish, forebode, foreshadow, foreshow, foretoken,
   furnish evidence, give evidence, give indication of, give sign,
   give token, go to show, highlight, hint, identify, illuminate,
   illustrate, imply, import, incarnate, indicate, involve,
   make clear, make plain, manifest, mark, materialize, mean, note,
   omen, parade, perform, point to, portend, prefigure, preindicate,
   presage, present, presign, presignal, presignify, pretypify,
   produce, promise, refer to, represent, reveal, roll out, set forth,
   show, show forth, show signs of, signalize, signify,
   speak for itself, speak volumes, spell, spotlight, stand for,
   suggest, symbolize, symptomatize, symptomize, tell, tend to show,
   testify, token, trot out, typify, unfold, wave, witness