I. ˈrē-ˌfleks noun
Etymology: Latin reflexus, past participle of reflectere to reflect
Date: 1508
1.
a. archaic : reflected heat, light, or color
b. : a mirrored image
c. : a copy exact in essential or peculiar features
2.
a. : an automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to a nerve center and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness — compare habit 7
b. : the process that culminates in a reflex and comprises reception, transmission, and reaction — called also reflex action
c. plural : the power of acting or responding with adequate speed
d. : a way of thinking or behaving
3. : a linguistic element (as a word or sound) or system (as writing) that is derived from a prior and especially an older element or system
boat is the reflex of Old English bāt
II. adjective
Etymology: Latin reflexus
Date: 1649
1. : directed back on the mind or its operations : introspective
2. : reflexed
3. : produced or carried out in reaction, resistance, or return
4. of an angle : being between 180° and 360°
5. : of, relating to, or produced by a reflex without intervention of consciousness
• re·flex·ly adverb