reflex Definition

reflex
noun reflexes

1. physiol.
A response to a sensory, physical or chemical stimulus, either a simple reflex which is a rapid automatic response (usually noxious) acting through local sensory cells linked to the spinal cord, or a conditioned reflex involving a slower brain-mediated response to prior learning or experience.
Form: reflex action (also)
2. The ability to respond rapidly to a stimulus.
3a. Reflected light, sound, heat, etc;
3b. A reflected image.
4. A sign or expression of something.
5. linguistics.
A word or element of speech which has developed from a corresponding earlier form.

adj

1. Occurring as an automatic response without being thought about.

Thesaurus: unthinking, mechanical, automatic, spontaneous, knee-jerk (slang), habitual.
2. Bent or turned backwards.
3. Directed back on the source; reflected.
4. Said of a thought: introspective.
5. math.
Denoting an angle that is greater than 180° but less than 360°. Compare acute (adj 7), obtuse (sense 3).

verb

reflexes, reflexed, reflexing
1. To bend something back.

Etymology: 16c: from Latin reflexus bent back.