chief, principal, main, major, leading, capital, foremost, primary

名詞 main:

1. any very large body of (salt) water
   同義詞：briny
2. a principal pipe in a system that distributes water or gas or electricity or that collects sewage

形容詞 main:

1. most important element
   同義詞：chief, primary, principal
2. (of a clause) capable of standing syntactically alone as a complete sentence
   同義詞：independent
3. of force; of the greatest possible intensity

1. The speech was most disappointing; it skirted round all the main questions.
   這篇演講非常令人失望，它回避了所有主要的問題。
2. The main road was flooded so we had to go round by narrow country lanes.
   公路干線遭水淹沒，我們只得擇鄉(xiāng)間小徑繞行。
3. By defeating their main competitor this firm has cornered the wheat market.
   這家公司擊敗了主要的競爭對手而壟斷了整個小麥市場。
4. The teacher asked me to note down the main points of the speech.
   老師要求我把演說的要點記下來。
5. I turned the gas off at the mains before I went out.
   我出門之前，把煤氣的總閥關掉了。

main

adj.（形容詞）
Most important; principal.See Synonyms at chief
最重要的；主要的參見 chief
Exerted to the utmost; sheer:
發(fā)揮到最大程度的；絕對的：
例句：
by main strength.
用全部力量

Nautical Connected to or located near the mainmast:
【航?！?/i> 和主桅有關的或者在主桅附近的：
例句：
a main skysail.
主桅天帆

Grammar Of, relating to, or being the principal clause or verb of a complex sentence.
【語法】 主句的、與之有關的或主句本身或復合句中的動詞
Obsolete Of or relating to a continuous area or stretch, as of land or water.
【廢語】 連綿不斷的水面或土地的區(qū)域或空間的或與之有關的
n.（名詞）
The chief or largest part:
主要的或最大的部分：
例句：
His ideas are, in the main, impractical.
總體來說，他的想法是不切實際的

The principal pipe or conduit in a system for conveying water, gas, oil, or other utility.
主要管道：輸送水、天然氣、石油系統(tǒng)中的主要管道或溝渠或其他公用事業(yè)設備
Physical strength:
體力：
例句：
fought with might and main.
竭盡全力地戰(zhàn)斗

A mainland.
大陸
The open ocean.
公海
Nautical
【航海】
A mainsail.
主帆
A mainmast.
主桅

來源：
Middle English
中古英語
from Old English môgen [strength] * see magh-
源自 古英語 môgen [力量] *參見 magh-