Meaning & use
not established
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Meanings
phrasefixed phraseformal
Not proven, confirmed, or shown to be true; not yet officially set up or agreed.
Grammar: Used after a linking verb such as be, remain, or seem: The cause remains not established.
Patterns
- something is not established
- something remains not established
- it is not established that …
The exact cause of the accident is not established.
It is not established that the drug works in children.
The committee said the facts were not established beyond doubt.
phrasefixed phraseformal
Not yet officially created, recognized, or put in place.
Grammar: Often describes institutions, rules, or relationships that do not yet formally exist.
Patterns
- a rule is not established
- a link is not established
A clear link between the two events is not established.
At that time, the university was not established.
Common combinations
- remain not established
- The link between diet and the illness remains not established.
- not established by law
- The right is not established by law in every country.
- not established beyond doubt
- The claim is not established beyond doubt.
- yet to be established
- The full effects are yet to be established.
Synonyms and how they differ
- unproven
- A single adjective; it fits better before a noun, as in an unproven theory.
- unconfirmed
- Suggests reports or information that have not yet been checked, rather than things that lack proof.
- undetermined
- Focuses on a decision or amount that has not been settled, not on proof.
Opposites
Word family
- establish verb
- To prove something or set it up officially.
- establishment noun
- The act of setting something up, or an organization.
- established adjective
- Accepted, proven, or long in existence.
Commonly confused: not established or unestablished?
not established vs unestablished
This adjective means 'not yet having a secure position or reputation', as in an unestablished writer. 'Not established' is used for facts, rules, and official arrangements.
Practice
Which sentence uses 'not established' most naturally?
Choose one answer.
'Not established' means 'not proven or confirmed', so it fits a fact or claim, as in option 1. Option 0 wrongly uses it for a physical location, and options 2 and 3 are ungrammatical.
Make it your own
Write a sentence using “not established”, then check it and compare it with the examples above.