momentous
[adjective]
Synonyms: significant, critical, crucial, fateful, historic, important, pivotal, vital, weighty

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Antonyms: trivial

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English Thesaurus: important, big, significant, noteworthy, essential, ...

[TahlilGaran] English Synonym Dictionary ▲

mo‧men‧tous /məʊˈmentəs, mə- $ moʊ-, mə-/ adjective
[Word Family: noun: moment, momentum; adjective: momentary, momentous; adverb: momentarily]
a momentous event, change, or decision is very important because it will have a great influence on the future:
a momentous decision
Momentous events are taking place in the US.
His colleagues all recognized that this was a momentous occasion.
one of the most momentous days in British sport

[TahlilGaran] Dictionary of Contemporary English ▲

important having a big effect on people’s lives or on events in the future:
an important decision
Good qualifications are increasingly important.
big important or serious:
It’s a big decision.
a big problem
significant important enough to be noticeable or have a big effect:
There is no significant difference between the performance of male and female students.
The Internet has brought about significant changes in people’s lives.
noteworthy formal important or interesting enough to deserve your attention:
The castle is the island’s most noteworthy feature.
The jury’s verdict was noteworthy for a number of reasons.
essential very important, especially for the success, health, or safety of someone or something:
It is essential to speak the local language.
essential supplies of food and clothing
vital/crucial extremely important, because without it there could be serious problems:
His evidence was vital to the case.
The US plays a crucial role in the region.
The media are a vital part of the political system.
key extremely important and having a big effect:
Wheeler had a key role in the development of the atom bomb.
Timing is key.
of great/considerable importance very important:
In the construction industry, health and safety are of considerable importance.
momentous very important because it has a very great effect on the future:
Momentous events were taking place in Russia.
a momentous decision
main/chief/principal [only before noun] most important:
What was your main aim?
the principal reason for their decision
the chief cause of the recession
major [usually before noun] one of the most important or serious things:
Smoking is a major cause of heart disease.
Street crime is a major problem.
central/primary [usually before noun] most important – used especially when talking about the main thing that people are discussing, worried about, or trying to do:
Education will be the central issue in the election.
Our primary concern is passenger safety.
paramount /ˈpærəmaʊnt/ formal more important than anything else, so that you must consider it when deciding what to do:
Airport security is of paramount importance.
The needs of the students are paramount.

[TahlilGaran] English Thesaurus ▲