1 MAINlarger or more important than all other things, ideas etc of the same kind 〔同类中〕最大的，最重要的► see thesaurus at important
2 the main thing spokenIMPORTANT used to say what is the most important thing in a situation 最重要的事
→ an eye for/on/to the main chance at eye1(22)Examples from the Corpus
the main thing• Enjoy them, that's the main thing!• Still it was appreciated and thats the main thing.• We had all this unused energy, that is the main thing I remember.• As for the LeBaron, the main thing in its favour was that the roof came off.• Listen, the main thing is, he's happy.• But the main thing is the link with Kahlenbergerdorf.• The main thing is to impress Bora and get on the team.• This thing of being a hero, about the main thing is to know when to die.• Saving the peace plan is the main thing right now.• That was the main thing, there was very little money, so we charged everything.
THESAURUS
main larger or more important than all the others 〔同类中〕最大的，最重要的，主要的
the main entrance of the building
大楼的大门
the main reason for his decision
他作这个决定的主要原因
chief/principal most important. Chief and principal are more formal than main, and are often used in written English 最重要的，主要的〔chief和principal比main更为正式，常用于书面英语中〕
Coffee is the country’s principal export.
咖啡是该国的主要出口商品。
What is the company’s chief objective?
该公司的主要目标是什么？
major very important or serious 重大的；主要的
Smoking is a major cause of heart disease.
吸烟是引发心脏病的主要原因。
Street crime is becoming a major problem.
街头犯罪逐渐成为一个重大问题。
key most important, or the one that everything or everyone else depends on 至关重要的；必不可少的，关键的
Education is likely to be a key issue in the election campaign.
教育可能是竞选活动的一个关键问题。
Hooper was a key member of the team.
胡珀是队里最为重要的一员。
Diet is key.
饮食至关重要。
number one especially spoken most important or best – this phrase sounds a little informal and it is used especially in spoken English 最重要的；最好的（略为不正式，尤用于英语口语〕
Reliability is the number one priority.
可靠性是头等大事。
the number one cause of death
头号死因
He is still in the number one position.
他仍坐头把交椅。
primary most important – used especially about the most important aim, role, cause, or concern. Primary is more formal than main 〔目的、作用、原因或担心的事〕首要的，主要的〔primary比main更为正式〕
The primary aim of the project was to help students develop their communication skills.
该计划的主要目的是帮助学生提高沟通技巧。
Security is our primary concern.
安全是我们最关注的事。
nThe primary function of the university was considered to be the teaching of ‘the great cultural disciplines’.
prime very important or most important – used especially about the most important reason, cause, or aim, or about the most likely target or suspect. Prime is more formal than main 〔原因、目的、目标或怀疑对象〕极为重要的，最重要的〔prime比main更为正式〕
Their prime objective is to increase profits for their shareholders.
他们的首要目标是提高股东收益。
Tourists are prime targets for theft and robbery.
游客是盗窃及抢劫的主要对象。
core most important – used especially about the things that people should pay most attention to 最重要的，核心的
the core skills of reading and writing
读写基本技能
He wants the company to focus on its core business – advertising.
他希望公司把注意力集中于核心业务——广告。
nThe party’s core values are individual freedom and reducing the amount of government bureaucracy.
central most important and having more influence than anything else 至关重要的，主要的
The U.S. played a central role in the peace negotiations.
美国在和平谈判中起了重要作用。
a central theme of the book
该书的主题
nThe central question is, why are people still so attached to their cars?