The Collaborative International Dictionary of English v.0.48:

Allege \Al*lege"\ ([a^]l*l[e^]j"), v. t. [imp. & p. p. Alleged
   (-l[e^]jd"); p. pr. & vb. n. Alleging.] [OE. aleggen to
   bring forward as evidence, OF. esligier to buy, prop. to free
   from legal difficulties, fr. an assumed LL. exlitigare; L. ex
   + litigare to quarrel, sue (see Litigate). The word was
   confused with L. allegare (see Allegation), and lex law.
   Cf. Allay.]
   1. To bring forward with positiveness; to declare; to affirm;
      to assert; as, to allege a fact.
      [1913 Webster]

   2. To cite or quote; as, to allege the authority of a judge.
      [Archaic]
      [1913 Webster]

   3. To produce or urge as a reason, plea, or excuse; as, he
      refused to lend, alleging a resolution against lending.
      [1913 Webster]

   Syn: To bring forward; adduce; advance; assign; produce;
        declare; affirm; assert; aver; predicate.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Allege \Al*lege"\, v. t. [See Allay.]
   To alleviate; to lighten, as a burden or a trouble. [Obs.]
   --Wyclif.
   [1913 Webster]

WordNet (r) 3.0 (2006):

allege
    v 1: report or maintain; "He alleged that he was the victim of a
         crime"; "He said it was too late to intervene in the war";
         "The registrar says that I owe the school money" [syn:
         allege, aver, say]

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "allege":
   accuse, acknowledge, adduce, advance, affirm, announce, annunciate,
   argue, arraign, array, article, assert, assever, asseverate,
   attest, aver, avouch, avow, bear witness, book, bring accusation,
   bring charges, bring forward, bring on, bring to bear,
   bring to book, certify, charge, cite, claim, complain, contend,
   declare, denounce, denunciate, deploy, depone, depose, disclose,
   enunciate, express, fasten on, fasten upon, finger, give evidence,
   hang something on, have, hold, impeach, imply, impute, indict,
   inform against, inform on, insinuate, insist, issue a manifesto,
   lay, lay charges, lay down, lodge a complaint, lodge a plaint,
   maintain, manifesto, marshal, nuncupate, offer, pin on, plead,
   predicate, prefer charges, present, press charges, pretend,
   pretext, proclaim, produce, profess, pronounce, protest,
   protest too much, purport, put, put it, put on report, quote,
   rally, recite, recount, rehearse, relate, report, reproach, say,
   set down, speak, speak out, speak up, stand for, stand on, state,
   submit, swear, take to task, task, taunt with, tax, testify, twit,
   vouch, warrant, witness