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

The Devil's Dictionary (1881-1906):

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