The Collaborative International Dictionary of English v.0.48:

Debate \De*bate"\, v. t. [imp. & p. p. Debated; p. pr. & vb.
   n. Debating.] [OF. debatre, F. d['e]battre; L. de + batuere
   to beat. See Batter, v. t., and cf. Abate.]
   1. To engage in combat for; to strive for.
      [1913 Webster]

            Volunteers . . . thronged to serve under his banner,
            and the cause of religion was debated with the same
            ardor in Spain as on the plains of Palestine.
                                                  --Prescott.
      [1913 Webster]

   2. To contend for in words or arguments; to strive to
      maintain by reasoning; to dispute; to contest; to discuss;
      to argue for and against.
      [1913 Webster]

            A wise council . . . that did debate this business.
                                                  --Shak.
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            Debate thy cause with thy neighbor himself. --Prov.
                                                  xxv. 9.

   Syn: To argue; discuss; dispute; controvert. See Argue, and
        Discuss.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Debate \De*bate"\, v. i.
   1. To engage in strife or combat; to fight. [Obs.] --Chaucer.
      [1913 Webster]

            Well could he tourney and in lists debate.
                                                  --Spenser.
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   2. To contend in words; to dispute; hence, to deliberate; to
      consider; to discuss or examine different arguments in the
      mind; -- often followed by on or upon.
      [1913 Webster]

            He presents that great soul debating upon the
            subject of life and death with his intimate friends.
                                                  --Tatler.
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The Collaborative International Dictionary of English v.0.48:

Debate \De*bate"\, n. [F. d['e]bat, fr. d['e]battre. See
   Debate, v. t.]
   1. A fight or fighting; contest; strife. [Archaic]
      [1913 Webster]

            On the day of the Trinity next ensuing was a great
            debate . . . and in that murder there were slain . .
            . fourscore.                          --R. of
                                                  Gloucester.
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            But question fierce and proud reply
            Gave signal soon of dire debate.      --Sir W.
                                                  Scott.
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   2. Contention in words or arguments; discussion for the
      purpose of elucidating truth or influencing action; strife
      in argument; controversy; as, the debates in Parliament or
      in Congress.
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            Heard, noted, answer'd, as in full debate. --Pope.
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   3. Subject of discussion. [R.]
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            Statutes and edicts concerning this debate.
                                                  --Milton.
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WordNet (r) 3.0 (2006):

debate
    n 1: a discussion in which reasons are advanced for and against
         some proposition or proposal; "the argument over foreign
         aid goes on and on" [syn: argument, argumentation,
         debate]
    2: the formal presentation of a stated proposition and the
       opposition to it (usually followed by a vote) [syn: debate,
       disputation, public debate]
    v 1: argue with one another; "We debated the question of
         abortion"; "John debated Mary"
    2: think about carefully; weigh; "They considered the
       possibility of a strike"; "Turn the proposal over in your
       mind" [syn: consider, debate, moot, turn over,
       deliberate]
    3: discuss the pros and cons of an issue [syn: debate,
       deliberate]
    4: have an argument about something [syn: argue, contend,
       debate, fence]

Moby Thesaurus II by Grady Ward, 1.0:

234 Moby Thesaurus words for "debate":
   Kilkenny cats, address, after-dinner speech, agitate, air, airing,
   allocution, altercation, analysis, analyze, application, argue,
   argument, argumentation, back down, balance, be abstracted,
   bickering, brood, buzz session, canvass, canvassing,
   cat-and-dog life, chalk talk, chew the cud, cloture, cogitation,
   colloquium, combat, comment upon, committee consideration,
   concentration, conference, conflict, consider, consideration,
   contemplate, contemplation, contend, contention, contentiousness,
   contest, contestation, controversy, controvert, cut and thrust,
   deal with, debating, declaim, declamation, deliberate,
   deliberate upon, deliberation, demagogue, demur, dialectic,
   dialogue, diatribe, digest, discept, discourse about, discuss,
   discussion, disputation, dispute, division, elocute, enmity,
   eulogy, examination, examine, exchange of views, exchange views,
   exhortation, falter, fear, fighting, filibuster, filibustering,
   filing, first reading, forensic, forensic address, formal speech,
   forum, funeral oration, go into, handle, hang back, harangue, heed,
   hem and haw, hesitate, hold forth, hortatory address, hostility,
   hover, hum and haw, inaugural, inaugural address, introduction,
   introspect, invective, investigate, investigation, jeremiad, jib,
   joint discussion, knock around, litigation, logical analysis,
   logical discussion, logomachy, logrolling, meditate, meditation,
   moot, mouth, mull over, muse, open discussion, open forum, orate,
   oration, out-herod Herod, panel discussion, paper war,
   pass under review, pause, pep talk, perorate, peroration, perpend,
   philippic, pitch, play around with, play with, polemic, ponder,
   ponder over, prepared speech, prepared text, public speech,
   pull back, quarrel, quarreling, quarrelsomeness, question,
   rabble-rouse, rant, rap, rap session, read, reading, reason,
   reason about, reason the point, recital, recitation, recite,
   reflect, reflection, refuting, retreat, review, rodomontade,
   roll call, ruminate, ruminate over, sales talk, salutatory,
   salutatory address, say, scrapping, screed, scruple,
   second reading, seminar, set speech, shilly-shally, shy, sift,
   speculate, speech, speechification, speeching, spiel, spout,
   squabbling, steamroller methods, stick at, stickle,
   stop to consider, straddle the fence, strain at, strife, struggle,
   study, symposium, tabling, take up, talk, talk about, talk of,
   talk over, talkathon, think over, think through, think twice about,
   third reading, thrash out, thresh out, tirade, toss, town meeting,
   toy with, treat, treatment, tub-thump, valediction, valedictory,
   valedictory address, ventilate, ventilation, vote, war,
   war of words, warfare, weigh, withdraw, words, wrangle, wrangling,
   yield



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

DEBATE, legislation, practice. A contestation between two or more persons,
in which they take different sides of a question, and maintain them,
respectively, by facts and arguments; or it is a discussion, in writing, of
some contested point.
     2. The debate should be conducted with fairness, candor and decorum,
and supported by facts and arguments founded in reason; when, in addition,
it is ornamented by learning, and decorated by the powers of rhetoric, it
becomes eloquent and persuasive. It is essential that the power of debate
should be free, in order to an energetic discharge of his duty by the
debator.
     3. The Constitution of the United States, art. 1, s. 6, provides, that
for any speech or debate, in either house, the senators and representatives
shall not be questioned in any other place.
     4. It is a rule of the common law, that counsel may, in, the discharge
of professional duty, use strong epithets, however derogatory to the
character of the opponent, or his attorney, or other agent or witness, in
commenting on the facts of the case, if pertinent to the cause, and stated
in his instructions, without any liability to any action for the supposed
slander, whether the thing stated were true or false. 1 B. & Ald. 232; 3
Dow's R. 273, 277, 279; 7 Bing. R. 459; S. C. 20 E. C. L. R. 198.
Respectable and sensible counsel, however, will always refrain from the
indulgence of any unjust severity, both on their own personal account, and
because browbeating a witness, or other person, will injuriously affect
their case in the eyes of a respectable court and jury. 3 Chit. Pr. 887, 8.