reflex
reflex — noun
1. An automatic body response to something that happens, such as a tap just below t
An automatic body response to something that happens, such as a tap just below the knee making the lower leg kick forward, which happens without conscious thought.
During the check-up, Dr. Okafor tapped Noor's knee with a small hammer to test her reflex.
stimulus-response pattern: tap knee → leg kick
Pulling your hand from a hot stove is an automatic reflex that protects you from burns.
The doctor shone a bright light into Sora's eyes to check whether her pupil reflex was working normally.
Blinking when something flies toward your face is a natural reflex that most people have.
When the nurse touched the back of Imani's throat with a swab, her gag reflex made her cough.
- instinct
broader — instinct covers complex behaviors (nest-building, migration), while reflex refers only to simple physical responses
- involuntary response
more formal and descriptive; less common in everyday speech
- voluntary action
an action you decide to do on purpose, the opposite of an automatic reflex
文法句型
reflex + to + stimulus
possessive + reflex
用法筆記
Commonly followed by the preposition 'to' to name the stimulus — for example, a reflex to light or a reflex to sound. Also appears in compound terms naming specific body reflexes, such as knee-jerk reflex, pupil reflex, and gag reflex.
常見錯誤
2. The natural speed with which a person responds physically or mentally to somethi
The natural speed with which a person responds physically or mentally to something sudden or unexpected — for example, catching a falling object or swerving to avoid a car.
Ravindra's quick reflexes helped him catch the falling glass before it hit the kitchen floor.
collocation: quick reflexes
Top tennis players need excellent reflexes to return serves that travel very fast.
collocation: excellent reflexes
Maeve practises racing games every day to sharpen her reflexes and hand-eye coordination.
Driving in heavy rain demands good reflexes because the car ahead may brake without warning.
- reaction time
more specific — measures the exact time interval; reflexes is broader and more natural in everyday speech
- quickness
general term for speed; less specific to responding to events
文法句型
possessive + reflexes
good/quick/lightning + reflexes
用法筆記
Almost always appears in the plural form 'reflexes' when referring to a person's general ability to react quickly. The singular 'reflex' in this sense is rare and usually occurs in set phrases like 'a lightning reflex'.
常見錯誤
3. A modern word or sound that has developed from a specific word or sound in an ol
A modern word or sound that has developed from a specific word or sound in an older form of the same language or a parent language.
Yael pointed at the whiteboard, showing how Latin 'lac' became Spanish 'leche' over time.
pattern: reflex of [source language word]
Ryo flipped through an Old English dictionary to find the reflex of the modern word 'loaf'.
Gabriela raised her hand in class to ask whether French 'père' is a reflex of a Latin word.
Ishaan traced the word 'brother' through three old manuscripts in the university archive.
- descendant
more general term for anything that develops from an earlier form; less technical than reflex
- derivative
broader — can refer to words formed by adding affixes, not just historical development
- ancestor
the earlier word from which a reflex develops
文法句型
reflex + of + source language word
用法筆記
A technical term in historical linguistics. The source language is usually specified after the preposition 'of'. Contrast with 'cognate', which refers to related words in sister languages that share a common ancestor rather than one deriving from the other.
reflex — adjective
1. Describes an angle that is larger than a straight line (180°) but smaller than a
Describes an angle that is larger than a straight line (180°) but smaller than a full circle (360°).
Linh used a protractor to measure the 210-degree reflex angle on her woodworking plan.
geometry tool: protractor + reflex angle
Benjamin drew a reflex angle of 230 degrees for his geometry homework last night.
geometry term: reflex angle + degree measurement
When the clock reads 7 o'clock, the minute hand and the hour hand form a reflex angle.
The teacher asked Zola to find the reflex angle among the three shapes on the worksheet.
- acute
an angle smaller than 90°, the opposite end of the angle-size spectrum
文法句型
reflex angle
be + reflex
用法筆記
Used only as an attributive adjective before 'angle' (reflex angle) or after a linking verb with 'angle' as the subject (This angle is reflex). Beyond geometry, this adjective form is not used.
常見錯誤
2. Happening as an immediate, unthinking physical or mental response rather than th
Happening as an immediate, unthinking physical or mental response rather than through conscious choice — for example, jerking your hand away from a hot surface before you feel the pain.
Obi's reflex action was to grab the toddler's arm before she ran into the busy street.
collocation: reflex action
The driver's reflex response to the deer in the road was to hit the brakes without thinking.
collocation: reflex response
Saira's reflex move of covering her face with both hands protected her eyes from the dust cloud.
A reflex cough or a sneeze can spread germs to other people in the same room.
João jumped back in a reflex movement when the wasp flew close to his face.
- automatic
more common and broader in use; 'automatic' can describe machines, while 'reflex' is limited to living beings' responses
- involuntary
more formal; used in medical and scientific writing about muscle movements
- instinctive
suggests a deeper behavioral drive rather than a simple physical response
- voluntary
describes an action done by conscious choice, the opposite of a reflex action
- deliberate
suggests careful thought before acting
文法句型
reflex + action/response/reaction
用法筆記
Used only before a noun — you can say 'a reflex action' but not 'His action was reflex'. The noun sense 1 (INVOLUNTARY MOVEMENT) conveys a similar meaning but focuses on the physiological mechanism rather than describing the quality of an action.