Also found in: Thesaurus, Medical, Legal, Encyclopedia, Wikipedia.


1. Physiology Being an involuntary action or response, such as a sneeze, blink, or hiccup.
2. Produced as an automatic response or reaction: reflex opposition to change.
3. Bent, turned, or thrown back; reflected.
4. Reflexed.
a. Physiology An involuntary response to a stimulus.
b. reflexes A person's ability to respond to new or changing stimuli: His quick reflexes make him a good taxi driver.
2. Psychology An unlearned or instinctive response to a stimulus.
3. Linguistics A form or feature that reflects or represents an earlier, often reconstructed, form or feature having undergone phonetic or other change.
a. Something, such as light or heat, that is reflected.
b. An image produced by reflection.
c. A copy or reproduction.

[From Middle English reflexen, to refract light, bend back, from Latin reflexus, past participle of reflectere, to bend back; see reflect.]


Acts that occur involuntarily—such as blinking—are the result of a reflex response.
References in classic literature ?
I made notes of my patient's pulse and temperature, tested the rigidity of his muscles, and examined his reflexes.
My pulse upon examination was ten beats above the usual, and my reflexes were increased.
Blink reflexes in chronic tension-type headache patients and healthy controls.
As we rotate our heads and as the world around us moves, two ocular reflexes kick in to offset this movement and stabilize images projected onto our retinas, the light-sensitive tissue at the back of our eyes.
On the whole, the recruitment curve consisted of 45 reflexes elicited at different nine electrical stimulation intensities (5 successive recorded H-reflexes in each intensity).
Retinoblastoma is suggested by a whitening of the reflex, white spots in the reflex, an absent red reflex, or asymmetry of the two red reflexes when viewed from various angles.
Individual bone and muscle structures of the orofacial area with face, oral cavity, pharynx and oesophagus muscles in particular--participate in: primitive oral reflexes, physiological breathing and breathing while speaking, intake of food and fluids, orofacial sensory, orofacial self-stimulation, face mimics and articulation.
Sensitivity of monosynaptic test reflexes to facilitation and inhibition as a function of the test reflex size: a study in man and the cat.
The fear paralysis reflex (FPR) may be described as one of the many primitive reflexes that all primates possess.
THE AMAZING THINGS YOUR NEW BABY CAN DO All babies have certain automatic movements they're born with - reflexes that help them protect themselves.
Spasticity is a complicated clinical symptom, characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex [3].
For instance, ballet dancers have been shown to have smaller than normal muscle stretch reflexes, (1) which could be a specific neural adaptation to maintain correct positions and perform various movements required for dance.