Definition of "reflex" in English

noun

1. An automatic response to a simple stimulus which does not require mental processing.

   • For a while, I shall have to make a conscious effort to smile, nod, stand and perform the thousands of little gestures which constitute life on Earth, and then those gestures will become reflexes again.

2. (linguistics) The descendant of an earlier language element, such as a word or phoneme, in a daughter language.

3. (linguistics, rare) The ancestor word corresponding to a descendant.

4. The descendant of anything from an earlier time, such as a cultural myth.

5. (chiefly photography) A reflection or an image produced by a reflection; the light reflected from an illuminated surface to one in shade.

   • A reflex camera uses a mirror to reflect the image onto a ground-glass viewfinder.

adjective

1. Bent, turned back or reflected.

2. Produced automatically by a stimulus.

3. (geometry, of an angle) Having greater than 180 degrees but less than 360 degrees.

   • If the reflex region is the interior of the angle, the dihedral angle is reflex.
   • P denotes a polygon and r the number of reflex vertices.

4. (painting) Illuminated by light reflected from another part of the same picture.

verb

1. (transitive) To bend back or turn back over itself.

2. (transitive, obsolete) To reflect (light, sight, etc.).

3. (transitive, obsolete) To reflect or mirror (an object), to show the image of.

4. (transitive, obsolete) To cast (beams of light) on something.

5. To respond to a stimulus.