The Collaborative International Dictionary of English v.0.48:

Response \Re*sponse"\ (r?*sp?ns"), n. [OF. response, respons, F.
   r['e]ponse, from L. responsum, from respondere. See
   Respond.]
   1. The act of responding.
      [1913 Webster]

   2. An answer or reply. Specifically:
      (a) Reply to an objection in formal disputation. --I.
          Watts.
      (b) (Eccl.) The answer of the people or congregation to
          the priest or clergyman, in the litany and other parts
          of divine service.
      (c) (R.C.Ch.) A kind of anthem sung after the lessons of
          matins and some other parts of the office.
      (d) (Mus.) A repetition of the given subject in a fugue by
          another part on the fifth above or fourth below.
          --Busby.
          [1913 Webster]

WordNet (r) 3.0 (2006):

response
    n 1: a result; "this situation developed in response to events
         in Africa"
    2: a bodily process occurring due to the effect of some
       antecedent stimulus or agent; "a bad reaction to the
       medicine"; "his responses have slowed with age" [syn:
       reaction, response]
    3: a statement (either spoken or written) that is made to reply
       to a question or request or criticism or accusation; "I
       waited several days for his answer"; "he wrote replies to
       several of his critics" [syn: answer, reply, response]
    4: the manner in which something is greeted; "she did not expect
       the cold reception she received from her superiors" [syn:
       reception, response]
    5: a phrase recited or sung by the congregation following a
       versicle by the priest or minister
    6: the speech act of continuing a conversational exchange; "he
       growled his reply" [syn: reply, response]
    7: the manner in which an electrical or mechanical device
       responds to an input signal or a range of input signals

Moby Thesaurus II by Grady Ward, 1.0:

226 Moby Thesaurus words for "response":
   Agnus Dei, Benedicite, ESP, Gloria, Gloria Patri,
   Gloria in Excelsis, Introit, Magnificat, Miserere, Nunc Dimittis,
   Te Deum, Trisagion, Vedic hymn, acknowledgment,
   action and reaction, affect, affection, alleluia, anacrusis,
   answer, answering, anthem, antiphon, antiphonal chanting,
   antiphony, argument, automatic reaction, autonomic reaction,
   awareness, back answer, back talk, backchat, backlash, backwash,
   bass passage, bounceback, bourdon, bridge, burden, cadence,
   canticle, caring, chant, chorale, chord, chorus, clout, coda,
   comeback, commerce, communication, communion, concern, congress,
   connection, consciousness, contact, conversation, converse,
   correspondence, counterstatement, dealing, dealings, defense,
   demurrer, denial, development, division, doxology, echo, effect,
   emotion, emotional charge, emotional shade, empathy, evasive reply,
   exception, exchange, experience, exposition, feedback, feeling,
   feeling tone, fellow feeling, figure, folderol, force, foreboding,
   gut reaction, hallelujah, harmonic close, heartthrob, hosanna,
   hymn, hymn of praise, hymnody, hymnography, hymnology,
   identification, impact, impress, impression, imprint, information,
   interaction, interchange, intercommunication, intercommunion,
   intercourse, interlude, intermezzo, interplay, introductory phrase,
   involvement, laud, linguistic intercourse, mantra, mark, measure,
   message, motet, movement, musical phrase, musical sentence,
   objection, offertory, offertory sentence, ornament, paean, part,
   passage, passion, pathos, percept, perception, period, phrase,
   plea, pleading, predictable response, presentiment, print,
   profound sense, psalm, psalmody, reaction, ready reply, rebuttal,
   receipt, recoil, reflection, reflex, reflex action, refluence,
   reflux, refrain, refutation, rejoinder, relating, repartee,
   repercussion, replication, reply, report, repost, rescript,
   rescription, resolution, respond, respondence, response to stimuli,
   responsion, responsiveness, responsory, responsory report, retort,
   retroaction, return, reverberation, revulsion, riposte, rise,
   ritornello, section, sensation, sense, sense impression,
   sense perception, sensory experience, sentiment, sharing,
   short answer, snappy comeback, social intercourse, speaking,
   special demurrer, special pleading, speech, speech circuit,
   speech situation, stanza, statement, statement of defense, strain,
   sympathetic chord, sympathetic response, sympathy, tailpiece,
   talking, telepathy, touch, traffic, truck, tutti, tutti passage,
   two-way communication, undercurrent, unthinking response,
   variation, verse, versicle, vibes, vibrations, witty reply,
   witty retort, yes-and-no answer