The Collaborative International Dictionary of English v.0.48:

Harangue \Ha*rangue"\, v. i. [imp. & p. p. Harangued
   (h[.a]*r[a^]ngd"); p. pr. & vb. n. Haranguing.] [Cf. F.
   haranguer, It. aringare.]
   To make an harangue; to declaim.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Harangue \Ha*rangue"\ (h[.a]*r[a^]ng"), n. [F. harangue: cf. Sp.
   arenga, It. aringa; lit., a speech before a multitude or on
   the hustings, It. aringo arena, hustings, pulpit; all fr.
   OHG. hring ring, anything round, ring of people, G. ring. See
   Ring.]
   A speech addressed to a large public assembly; a popular
   oration; a loud address to a multitude; in a bad sense, a
   noisy or pompous speech; declamation; ranting.
   [1913 Webster]

         Gray-headed men and grave, with warriors mixed,
         Assemble, and harangues are heard.       --Milton.

   Syn: Harangue, Speech, Oration.

   Usage: Speech is generic; an oration is an elaborate and
          rhetorical speech; an harangue is a vehement appeal to
          the passions, or a noisy, disputatious address. A
          general makes an harangue to his troops on the eve of
          a battle; a demagogue harangues the populace on the
          subject of their wrongs.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Harangue \Ha*rangue"\, v. t.
   To address by an harangue.
   [1913 Webster]

WordNet (r) 3.0 (2006):

harangue
    n 1: a loud bombastic declamation expressed with strong emotion
         [syn: harangue, rant, ranting]
    v 1: deliver a harangue to; address forcefully

Moby Thesaurus II by Grady Ward, 1.0:

97 Moby Thesaurus words for "harangue":
   address, after-dinner speech, allocution, assignment, chalk talk,
   debate, declaim, declamation, demagogue, diatribe, discourse,
   disquisition, elocute, eulogy, exercise, exhortation, explain,
   exposit, exposition, expound, filibuster, forensic,
   forensic address, formal speech, funeral oration, hold forth,
   homework, homily, hortatory address, inaugural, inaugural address,
   instruction, invective, jeremiad, lecture, lecture-demonstration,
   lesson, moral, moral lesson, morality, moralization, moralize,
   mouth, object lesson, orate, oration, out-herod Herod, pep talk,
   perorate, peroration, philippic, pitch, point a moral, pontificate,
   preach, preachment, prepared speech, prepared text, public speech,
   rabble-rouse, rant, rant and rave, rave, read, read a lesson,
   reading, recital, recitation, recite, rodomontade, sales talk,
   salutatory, salutatory address, say, screed, sermon, sermonize,
   set speech, set task, skull session, soapbox, speech,
   speechification, speeching, spiel, spout, talk, talkathon, task,
   teaching, tirade, tub-thump, valediction, valedictory,
   valedictory address, vituperate, vituperation



The Devil's Dictionary (1881-1906):

HARANGUE, n.  A speech by an opponent, who is known as an harrangue-
outang.