reflex

UK: ˈriːflɛks | US: ˈriːflɛks

Definition
  1. n. 1. An involuntary or instinctive physical response to a stimulus.

  2. n. 2. A reflected source of light, heat, or sound.

  3. adj. 1. (Of an action) performed without conscious thought as a reaction to a stimulus.

Structure
re <back>flex <bend>
Etymology

reflex = re<back> + flex<bend>

  • re: Latin prefix meaning "back" or "again."
  • flex: From Latin flectere, meaning "to bend."

Etymology Origin:
The word reflex originates from Latin reflectere (to bend back), combining re- (back) and flectere (to bend). It initially described physical phenomena like light or sound bouncing back, later extending to involuntary bodily reactions (e.g., a knee jerk) metaphorically "bending back" to a stimulus. The logic reflects a literal-to-figurative shift, mirroring the word’s core idea of reversal or response.

Examples
  1. The doctor tested her knee-jerk reflex with a small hammer.

  2. The reflex of sunlight on the water created a dazzling effect.

  3. Sneezing is a natural reflex to irritants in the nose.

  4. His quick reflexes saved him from falling off the bike.

  5. The cat’s reflex to pounce on moving objects is instinctive.