Infallible
/ɪnˈfæləbəl/
adjectiveC1
Definition
Infallible means that a person, idea, or thing is always correct and never wrong. It suggests complete trust because there is no chance of error or failure. People often use it to describe perfect knowledge or judgment.
Was this helpful?
See It in Action
Unable to make mistakes; always correct
- •The scientist was considered infallible in her field.
- •Many people believe that the human mind is not infallible.
- •The device is infallible and never breaks down.
Certain and reliable; cannot fail
- •The plan seemed infallible, but unexpected problems appeared.
- •His memory was infallible during the exam.
- •The system is designed to be infallible under normal conditions.
Make It Stick
- ✓Think of "infallible" like "right" (A1 word), but stronger—it means ALWAYS right, never wrong
- ✓Picture a clock that never stops or shows the wrong time, always perfect and exact
- ✓It's the feeling when you trust a very good friend who never forgets or makes a mistake
- ✓Sounds like "in-FALL-ible" → imagine someone who never FALLs or fails, always steady and correct
- ✓Think of superheroes or wise teachers in stories who always give perfect advice and never fail
- ✓NOT like "sometimes right" or "usually right"—infallible means no mistakes at all
- ✓NOT like "perfect" in appearance only—infallible means perfect in truth or judgment, not just looks
Try Other Words
- •Unerring: never making mistakes (Use when emphasizing accuracy without error)
- •Faultless: without any faults or mistakes (Use when focusing on being free from errors)
- •Reliable: able to be trusted to do something well (Use when focusing on trustworthiness rather than absolute perfection)
- •Certain: sure to happen or be true (Use when emphasizing confidence or surety)
Unboxing
- •Prefix "in-" means "not" or "without"
- •Root "fall" comes from Latin "fallere" meaning "to deceive" or "to fail"
- •Suffix "-ible" means "able to be"
- •Together, "infallible" means "not able to fail" or "not able to make mistakes"
- •First used in English in the late 15th century, often in religious or formal contexts to describe perfect truth or authority
- •Today, used in many areas like science, technology, or character to describe something or someone that cannot be wrong
Reflect & Connect
•Can anyone or anything truly be infallible in real life? Why or why not?
•How would believing something is infallible affect your trust in it or your own decisions?
Fill in the blanks
1.People often think experts are infallible because they ___ very knowledgeable and rarely make mistakes.
2.The idea that a person is infallible means they cannot ___ or be wrong.
3.Unlike normal humans, an infallible judge would ___ every decision correctly without error.
4.Saying a machine is infallible means it will ___ work without breaking or failing.
5.When someone acts as if they are infallible, they may not accept ___ from others.
6.The plan seemed infallible at first, but unexpected problems ___ it.
7.Infallible knowledge is considered ___ and always true, without any doubt.