[1] : The Collaborative International Dictionary of English v.0.48

echo \ech"o\ e^k"-o, n.; pl. echoes e^k"=oz. l.
   echo, gr. 'hchw` echo, sound, akin to 'hchh`, 'h^chos, sound,
   noise; cf. skr. v=a,c to sound, bellow; perh. akin to e.
   voice: cf. f. 'echo.
   1. a sound reflected from an opposing surface and repeated to
      the ear of a listener; repercussion of sound; repetition
      of a sound.
      1913 webster

            the babbling echo mocks the hounds.   --shak.
      1913 webster

            the woods shall answer, and the echo ring. --pope.
      1913 webster

   2. fig.: sympathetic recognition; response; answer.
      1913 webster

            fame is the echo of actions, resounding them.
                                                  --fuller.
      1913 webster

            many kind, and sincere speeches found an echo in his
            heart.                                --r. l.
                                                  stevenson.
      1913 webster

   3.
      a myth.  poetic a wood or mountain nymph, regarded as
          repeating, and causing the reverberation of them.
          1913 webster

                sweet echo, sweetest nymph, that liv'st unseen
                within thy airy shell.            --milton.
      b gr. myth. a nymph, the daughter of air and earth,
          who, for love of narcissus, pined away until nothing
          was left of her but her voice.
          1913 webster

                compelled me to awake the courteous echo
                to give me answer from her mossy couch.
                                                  --milton.
          1913 webster

   4. whist, contract bridge
      a a signal, played in the same manner as a trump signal,
          made by a player who holds four or more trumps or as
          played by some exactly three trumps and whose partner
          has led trumps or signaled for trumps.
      b a signal showing the number held of a plain suit when
          a high card in that suit is led by one's partner.
          webster 1913 suppl.

   echo organ mus., a set organ pipes inclosed in a box so
      as to produce a soft, distant effect; -- generally
      superseded by the swell.

   echo stop mus., a stop upon a harpsichord contrived for
      producing the soft effect of distant sound.

   to applaud to the echo, to give loud and continuous
      applause. --m. arnold.
      1913 webster

            i would applaud thee to the very echo,
            that should applaud again.            --shak.
      1913 webster
see also:
echoes echo organ echo stop to applaud to the echo 

[2] : The Collaborative International Dictionary of English v.0.48

echo \ech"o\, v. t. imp.  p. p. echoed; p. pr.  vb. n.
   echoing. -- 3d pers. sing. pres. echoes.
   1. to send back a sound; to repeat in sound; to
      reverberate.
      1913 webster

            those peals are echoed by the trojan throng.
                                                  --dryden.
      1913 webster

            the wondrous sound
            is echoed on forever.                 --keble.
      1913 webster

   2. to repeat with assent; to respond; to adopt.
      1913 webster

            they would have echoed the praises of the men whom
            they envied, and then have sent to the newspaper
            anonymous libels upon them.           --macaulay.
      1913 webster
see also:
echoed echoing echoes 

[3] : The Collaborative International Dictionary of English v.0.48

echo \ech"o\, v. i.
   to give an echo; to resound; to be sounded back; as, the hall
   echoed with acclamations. "echoing noise." --blackmore.
   1913 webster

[4] : WordNet (r) 2.0

echo
     n 1: the persistence of a sound after its source has stopped
          syn: reverberation, sound reflection, replication
     2: greek mythology a nymph who was spurned by narcissus and
        pined away until only her voice remained
     3: a reply that repeats what has just been said
     v 1: to say again or imitate; "followers echoing the cries of
          their leaders" syn: repeat
     2: ring or echo with sound; "the hall resounded with laughter"
        syn: resound, ring, reverberate
     3: call to mind; "his words echoed john f. kennedy" syn: recall
     also: echoes pl
see also:
reverberation sound reflection replication repeat resound ring 
reverberate recall echoes 

[5] : Moby Thesaurus II by Grady Ward, 1.0

289 moby thesaurus words for "echo":
   crt spot, dm display, doppler signal, if signal, im display,
   rf echoes, accord, acknowledge, acknowledgment, act like,
   action and reaction, adumbration, affect, agree, agree in opinion,
   agree with, answer, answer back, answering, antiphon,
   antiphonal chanting, antiphony, ape, assume, automatic reaction,
   autonomic reaction, back answer, back talk, backchat, be affected,
   be in tune, be inspired, be involved, be moved, be reflected,
   be sent back, beam, beat signal, blips, boom, booming, borrow,
   bounce back, bounceback, bounces, care about, caring,
   catch the flame, catch the infection, change color, chime in with,
   choir, chord, chorus, claviature, close with, coincide,
   color with emotion, come again, come back, come back at,
   come up again, comeback, concern, concur, conform to, conformist,
   console, copier, copy, copycat, copyist, counterfeit,
   counterfeiter, crib, cuckoo, dig, display, dissembler,
   dissimulator, ditto, do, do a repeat, do again, do like, do over,
   double, double-dot display, doubling, duplicate, duplication,
   echo back, echo signal, echoer, echoist, eighty-eight,
   empathize with, empathy, emulate, encore, evasive reply, facsimile,
   fake, faker, fall in with, fellow feeling, fingerboard, flash back,
   forge, forger, give acknowledgment, give answer, go along with,
   go back, go like, go with, great, growl, growling, grumble,
   grumbling, hoke, hoke up, hypocrite, identification, identify with,
   imitate, imitation, imitator, impersonator, impostor, involvement,
   iteration, ivories, keep coming, keyboard, keys,
   local oscillator signal, make like, manual, meet, mime, mimer,
   mimic, mimicker, mirror, mirror image, mocker, mockingbird, monkey,
   organ manual, outline, output signal, parrot, pathos, pedals,
   phony, piano keys, picture, pips, plagiarism, plagiarist,
   plagiarize, poll-parrot, polly, polly-parrot, poseur,
   predictable response, quotation, quote, radar signal, react,
   reaction, reading, ready reply, reappear, reappearance, rebirth,
   reboation, rebound, receipt, recur, recurrence, redo, redouble,
   redoubling, reduplicate, reduplication, reecho, reflect,
   reflection, reflex, reflex action, refluence, reflux, regurgitate,
   regurgitation, reincarnate, reincarnation, reiteration, rejoin,
   rejoinder, relate to emotionally, relating, renew, renewal,
   reoccur, reoccurrence, repartee, repeat, repeat performance,
   repercussion, repetition, replica, replication, reply, repost,
   reproduce, reproduction, rescript, rescription, resound,
   resounding, respond, respondence, response, responsion,
   responsiveness, responsory, responsory report, resume, resumption,
   retort, retroaction, return, return answer, return for answer,
   return signal, reverberate, reverberation, revert, revive,
   revulsion, ring, riposte, rise, roll, rumble, rumbling, say,
   say again, say in reply, send back, shadow, share, sharing, sheep,
   shoot back, short answer, side with, signal, signal display,
   silhouette, simulate, simulation, simulator, snappy comeback, solo,
   sound, spot, strike in with, swell, sympathetic chord,
   sympathetic response, sympathize with, sympathy, talk back,
   target image, thunder, thundering, trace, transmitter signal,
   unthinking response, vibes, vibrations, video signal, witty reply,
   witty retort, yes-and-no answer

[6] : Virtual Entity of Relevant Acronyms (Version 1.9, June 2002)

echo
     european community host organisation org., europe
     
     

[7] : Jargon File (4.3.1, 29 Jun 2001)

echo fidonet n. a topic group on fidonet's echomail system.
   compare newsgroup.


see also:
topic group fidonet newsgroup 

[8] : The Free On-line Dictionary of Computing (27 SEP 03)

echo
     
        1. a topic group on fidonet's echomail system.
     
        compare newsgroup.
     
        2. a unix command that just prints its arguments.
     
        jargon file
     
     
see also:
topic group fidonet echomail newsgroup unix jargon file 

[9] : U.S. Gazetteer (1990)

echo, mn city, fips 17900
  location: 44.62275 n, 95.41126 w
  population 1990: 304 145 housing units
  area: 2.6 sq km land, 0.0 sq km water
  zip codes: 56237
echo, or city, fips 22200
  location: 45.74395 n, 119.19203 w
  population 1990: 499 215 housing units
  area: 1.5 sq km land, 0.0 sq km water
  zip codes: 97826

[10] : U.S. Gazetteer Places (2000)

echo, or -- u.s. city in oregon
   population 2000:    650
   housing units 2000: 252
   land area 2000:     0.595598 sq. miles 1.542591 sq. km
   water area 2000:    0.000000 sq. miles 0.000000 sq. km
   total area 2000:    0.595598 sq. miles 1.542591 sq. km
   fips code:            22200
   located within:       oregon or, fips 41
   location:             45.741196 n, 119.194632 w
   zip codes 1990:     97826
   note: some zip codes may be omitted esp. for suburbs.
   headwords:
    echo, or
    echo

[11] : U.S. Gazetteer Places (2000)

echo, mn -- u.s. city in minnesota
   population 2000:    278
   housing units 2000: 136
   land area 2000:     1.017813 sq. miles 2.636124 sq. km
   water area 2000:    0.000000 sq. miles 0.000000 sq. km
   total area 2000:    1.017813 sq. miles 2.636124 sq. km
   fips code:            17900
   located within:       minnesota mn, fips 27
   location:             44.617088 n, 95.415071 w
   zip codes 1990:     56237
   note: some zip codes may be omitted esp. for suburbs.
   headwords:
    echo, mn
    echo

Echo >> E Words
Echo, definition of term: Echo
echo_pag1.html

Echo Sounding >> E Words
Echo Sounding, definition of term: Echo Sounding
echo+sounding_pag1.html