The Collaborative International Dictionary of English v.0.48:

Caution \Cau"tion\, n. [F. caution a security, L. cautio, fr.
   cavere (For scavere) to be on one's guard, to take care
   (orig.) to be on the watch, see; akin to E. show.]
   1. A careful attention to the probable effects of an act, in
      order that failure or harm may be avoided; prudence in
      regard to danger; provident care; wariness.
      [1913 Webster]

   2. Security; guaranty; bail. [R.]
      [1913 Webster]

            The Parliament would yet give his majesty sufficient
            caution that the war should be prosecuted.
                                                  --Clarendon.
      [1913 Webster]

   3. Precept or warning against evil of any kind; exhortation
      to wariness; advice; injunction.
      [1913 Webster]

            In way of caution I must tell you.    --Shak.
      [1913 Webster]

   4. (Civil & Scots Law) A pledge, bond, or other security for
      the performance of an obligation either in or out of
      judicial proceedings; the promise or contract of one not
      for himself but another; security.
      [Webster 1913 Suppl.]

   Caution money, money deposited by way of security or
      guaranty, as by a student at an English university.

   Syn: Care; forethought; forecast; heed; prudence;
        watchfulness; vigilance; circumspection; anxiety;
        providence; counsel; advice; warning; admonition.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Caution \Cau"tion\ v. t. [imp. & p. p. Cautioned; p. pr. & vb.
   n. Cautioning.]
   To give notice of danger to; to warn; to exhort [one] to take
   heed.
   [1913 Webster]

         You cautioned me against their charms.   --Swift.
   [1913 Webster]

WordNet (r) 3.0 (2006):

caution
    n 1: the trait of being cautious; being attentive to possible
         danger; "a man of caution" [syn: caution, cautiousness,
         carefulness] [ant: incaution, incautiousness]
    2: a warning against certain acts; "a caveat against unfair
       practices" [syn: caution, caveat]
    3: judiciousness in avoiding harm or danger; "he exercised
       caution in opening the door"; "he handled the vase with care"
       [syn: caution, precaution, care, forethought]
    4: the trait of being circumspect and prudent [syn:
       circumspection, caution]
    v 1: warn strongly; put on guard [syn: caution, admonish,
         monish]

Moby Thesaurus II by Grady Ward, 1.0:

163 Moby Thesaurus words for "caution":
   TLC, admonish, admonishment, admonition, advice, advise, advising,
   advocacy, alarm, alert, alerting, alertness, anticipation,
   attention, briefing, canniness, care, carefulness, caution money,
   cautioning, cautiousness, caveat, charge, circumspection,
   circumspectness, clue, collateral, collateral security, concern,
   consideration, consultation, council, counsel, cry havoc,
   cry out against, cue, daunt, deposit, determent, deterrence,
   deterrent example, diffidence, direction, discreetness, discretion,
   disinclination to believe, dissuade, encourage, enjoin, example,
   exhort, exhortation, expostulate, expostulation, falter, faltering,
   final notice, final warning, foresight, forethought, forewarn,
   forewarning, forfeit, frighten off, frightening off,
   give fair warning, give notice, give warning, guardedness,
   guidance, heed, heedfulness, hesitance, hesitancy, hesitating,
   hesitation, hint, hortation, idea, incite, inconvincibility,
   incredulity, induce, injunction, instruction, intimidate,
   intimidation, issue a caveat, issue an ultimatum, kid out of,
   leeriness, lesson, loving care, margin, mindfulness, monition,
   moral, move, notice, notification, notify, object lesson, office,
   opinion, parley, passing word, persuade, pointer, preach,
   precaution, preconsideration, predeliberation, premeditation,
   preparedness, prompt, proposal, providence, prudence,
   recommendation, regard, regardfulness, remonstrance, remonstrate,
   resistiveness to belief, shilly-shally, shilly-shallying,
   skepticism, solicitude, sound the alarm, stake, steer, suggestion,
   suspicion, suspiciousness, talk out of, talking out of,
   tender loving care, tentativeness, thought, thoughtfulness, threat,
   threaten, tip, tip off, tip-off, tough-mindedness, ultimatum,
   unconvincibility, uncredulousness, unpersuadability, unpersuade,
   unpersuasibility, urge, utter a caveat, verbum sapienti, vigilance,
   wariness, warn, warn against, warning, warning piece, watchfulness,
   whisper



Bouvier's Law Dictionary, Revised 6th Ed (1856):

CAUTION. A term of the Roman civil law, which is used in various senses. It
signifies, sometimes, security, or security promised. Generally every
writing is called cautio, a caution by which any object is provided for.
Vicat, ad verb. In the common law a distinction is made between a contract
and the security. The contract may be good and the security void. The
contract may be divisible, and the security entire and indivisible. 2 Burr,
1082. The securities or cautions judicially required of the defendant, are,
judicio sisti, to attend and appear during the pendency of the suit; de
rato, to confirm the acts of his attorney or proctor; judicium solvi, to pay
the sum adjudged against him. Coop. Just. 647; Hall's Admiralty Practice,
12; 2 Brown, Civ. Law, 356.



Bouvier's Law Dictionary, Revised 6th Ed (1856):

CAUTION, TURATORY, Scotch law. Juratory caution is that which a suspender
swears is the best he can offer in order to obtain a suspension. Where the
suspender cannot, from his low or suspected circumstances, procure
unquestionable security, juratory caution is admitted. Ersk. Pr. L. Scot. 4,
3, 6.