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

reflex \re"flex\ r?"fl?ks, a. l. reflexus, p. p. of
   reflectere: cf. f. r'eflexe. see reflect.
   1. directed back; attended by reflection; retroactive;
      introspective.
      1913 webster

            the reflex act of the soul, or the turning of the
            intellectual eye inward upon its own actions. --sir
                                                  m. hale.
      1913 webster

   2. produced in reaction, in resistance, or in return.
      1913 webster

   3. physiol. of, pertaining to, or produced by, stimulus or
      excitation without the necessary intervention of
      consciousness.
      1913 webster

   reflex action physiol., any action performed
      involuntarily in consequence of an impulse or impression
      transmitted along afferent nerves to a nerve center, from
      which it is reflected to an efferent nerve, and so calls
      into action certain muscles, organs, or cells.

   reflex nerve physiol., an excito-motory nerve. see
      exito-motory.
      1913 webster
see also:
reflect reflex action reflex nerve exito-motory 

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

34 moby thesaurus words for "reflex action":
   action and reaction, answer, automatic reaction, automatic writing,
   automatism, autonomic reaction, blind impulse, bounceback,
   compulsiveness, conditioning, echo, echolalia, echopraxia, impulse,
   instinct, instinctiveness, involuntariness, predictable response,
   reaction, reflection, reflex, refluence, reflux, reply,
   respondence, response, retroaction, return, reverberation,
   revulsion, rise, sheer chemistry, unthinking response,
   unwilledness

Action >> A Words
Action, definition of term: Action
action_pag1.html

Action Replay >> A Words
Action Replay, definition of term: Action Replay
action+replay_pag1.html

Action Potentia >> A Words
Action Potentia, definition of term: Action Potentia
action+potentia_pag1.html

Direct Action >> D Words
Direct Action, definition of term: Direct Action
direct+action_pag1.html

Civil Action >> C Words
Civil Action, definition of term: Civil Action
civil+action_pag1.html