inconsistent
gb/ˌɪŋkənsˈɪstənt/ us/ˌɪŋkənsˈɪstənt/
B2
English
~ 7900
Senses
0 senses
adjective
B2
property
1
not regular or stable
not the same each time; changing in a way you cannot easily predict
Usage pattern:
to be inconsistent in [something]
Common mistake:
Learners sometimes say *“inconsistence”* instead of the adjective *“inconsistent”*, or use *“not consistent”* when *“inconsistent”* is more natural and concise (e.g., *“His work is inconsistent,”* not *“His work is not consistent.”*).
Synonyms
irregular (suggests a pattern that does not follow a normal or expected rhythm or schedule.)
|
variable (focuses on the fact that something changes, without strongly implying it is a problem.)
|
erratic (stronger and often more negative, implying sudden, surprising, or worrying changes.)
Antonyms
consistent (stays the same in quality or behavior over time.)
|
steady (emphasizes smooth, stable, and reliable lack of change.)
Collocations
inconsistent results
|inconsistent performance
|inconsistent behavior
|inconsistent quality
|wildly inconsistent
|highly inconsistent
Themes
daily life
|work
|communication
|core_vocabulary
Examples
- The team's inconsistent performance made it impossible to know whether they would win or lose.
- Sales have been inconsistent this year, with some months far better than others.
- Her sleep schedule is so inconsistent that she often feels tired during the day.
- The Wi‑Fi signal is inconsistent, so the video keeps freezing.
- He was dropped from the starting lineup because of his inconsistent shooting.
Learner examples
- The weather is very inconsistent in spring.
- My internet is inconsistent, so I cannot watch movies easily.
- Her test scores are inconsistent from month to month.
- The machine is inconsistent and sometimes stops for no reason.
adjective
B2
property
2
not reliable in actions
often changing how you act or make decisions, so other people cannot depend on you or on the rules you use
Usage pattern:
to be inconsistent about [something]
Common mistake:
Learners may confuse *“inconsistent”* with *“inconsiderate”*. *“Inconsistent”* is about not acting the same way each time; *“inconsiderate”* means not thinking about other people’s feelings.
Synonyms
unreliable (strongly emphasizes that someone or something cannot be depended on.)
|
fickle (often about feelings or loyalties that change easily and unexpectedly.)
|
changeable (describes a tendency to change, sometimes without suggesting strong criticism.)
Antonyms
reliable (can be trusted to behave or perform in the same way each time.)
|
dependable (similar to ‘reliable’, especially for people you can count on over time.)
Collocations
inconsistent parenting
|inconsistent leadership
|inconsistent policy
|inconsistent standards
|inconsistent decision‑making
|inconsistent enforcement
Themes
relationships
|work
|emotions
|core_vocabulary
Examples
- He is a talented but inconsistent manager who changes his mind from one week to the next.
- Parents who are inconsistent with rules can confuse their children.
- The company has been inconsistent in how it applies its dress code.
- Her support has been inconsistent; some days she helps a lot, and other days she disappears.
- Judges must avoid inconsistent treatment of similar cases.
Learner examples
- My boss is inconsistent about deadlines.
- He is an inconsistent friend and often cancels plans.
- The teacher is inconsistent with homework rules.
- The coach is inconsistent and changes the team every game.
adjective
B2
property
3
not in agreement with something
not in agreement with something else; different in a way that makes it hard for both to be true or right at the same time
Usage pattern:
to be inconsistent with [something]
Common mistake:
Learners sometimes add an extra preposition and say *“inconsistent to”* or *“inconsistent for”*. The natural pattern is *“inconsistent with [something]”* (e.g., *“inconsistent with our policy”*).
Synonyms
conflicting (general word for things that do not fit together or agree.)
|
contradictory (stronger; suggests that if one thing is true, the other must be false.)
|
incompatible (cannot exist or work well together without causing problems.)
Antonyms
compatible (able to exist or be true together without conflict.)
|
in line (with) (used to say something matches or follows a rule, idea, or standard.)
Collocations
inconsistent with the evidence
|inconsistent with his story
|inconsistent with our values
|inconsistent with company policy
|mutually inconsistent
|inconsistent with previous statements
Themes
law
|science
|communication
|logic
|core_vocabulary
Examples
- His explanation is inconsistent with the facts we already know.
- The witness gave two statements that were clearly inconsistent with each other.
- The new proposal is inconsistent with the company’s long‑term strategy.
- Such comments are inconsistent with our values as an organization.
- The measurements are inconsistent with the theory they are supposed to support.
Learner examples
- His words are inconsistent with his actions.
- The report is inconsistent with the numbers in the table.
- Her story is inconsistent with what I saw.
- These rules are inconsistent with the law.
adjective
technical
C1
property
4
logically self‑contradictory
in logic or math, having ideas or rules that cannot all be true at the same time because they contradict each other
Usage pattern:
to be inconsistent as a [system/theory/set of axioms]
Synonyms
self‑contradictory (explicitly highlights that the system or set of statements contradicts itself.)
|
non‑coherent (less common; focuses on lack of internal logical unity rather than a sharp contradiction.)
Antonyms
consistent (in logic, means that no contradiction can be derived from the system or set of statements.)
Collocations
inconsistent axioms
|inconsistent system
|inconsistent theory
|inconsistent set of equations
|logically inconsistent
|mathematically inconsistent
Themes
logic
|mathematics
|philosophy
|science
|education
Examples
- If the axioms are inconsistent, the entire logical system collapses.
- The court rejected the argument as based on an internally inconsistent theory of liability.
- An inconsistent set of equations cannot all be satisfied by the same values.
Learner examples
- In math, an inconsistent system has a contradiction.
- A good theory should not be logically inconsistent.
- The professor showed that the old rules were inconsistent.
Grammar
Dictionary form
inconsistent
IPA
GB/ˌɪŋkənsˈɪstənt/
US/ˌɪŋkənsˈɪstənt/
Syllables & stress
in - con - sist - ent (4 syllables)
Stress on 3rd syllable (sist)
Word forms
Adjective
- Base: inconsistent
Word family
Core family
Related words
Expressions
inconsistent with
1/ˌɪŋkənsˈɪstənt wˈɪθ/
fixed phrase
not matching or agreeing with
used to say that one thing does not match, agree with, or fit another thing, such as a fact, rule, or promise
Examples
- His account of the accident is inconsistent with what other witnesses said.
- The judge found the new law to be inconsistent with the constitution.
- Skipping safety checks is inconsistent with our company policy.