middle

center, middle, heart, core, midst

这些名词均含有“中心”之意。
center: 指三维空间的中心点，也可比喻抽象事物的中心。
middle: 一般指时间、空间或过程两端间等距的部分。
heart: 指事物最内部或最重要的部分，表地理位置时可与center换用。
core: 指某事物固定的中心部分或最重要的核心部分。比喻意义指某物的精华。
midst: 书面语用词，指在一个群体的深处或在某活动的进程中。

名词 middle:

1. an area that is approximately central within some larger region
   同义词：center, centre, heart, eye
2. an intermediate part or section- Aristotle
3. the middle area of the human torso (usually in front)
   同义词：midriff, midsection
4. time between the beginning and the end of a temporal period

动词 middle:

1. put in the middle

形容词 middle:

1. being neither at the beginning nor at the end in a series
   同义词：in-between, mediate
2. equally distant from the extremes
   同义词：center, halfway, midway
3. of a stage in the development of a language or literature between earlier and later stages
4. between an earlier and a later period of time

1. The sheets have worn thin in the middle.
   床单的中间部分磨薄了。
2. There are 300 students or so in this middle school.
   这所中学大约有300个学生。
3. A boy rushed into the classroom in the middle of the exam.
   考试中间，有个男孩冲进了教室。
4. He is standing in the middle of the classroom.
   他正站在教室中间。
5. Farther than another from the center or middle.
   远离中心的比在中心处或中间的一个更远的
6. He planted roses in the middle of the garden.
   他在花园中间种上玫瑰。
7. The man has reached middle age.
   这人已到了中年。

mid.dle

adj.Abbr. mid.（形容词）缩写 mid.
Equally distant from extremes or limits; central:
当中的；中央的：离两端点或两界点等距离的；中央的：
例句：
the middle point on a line.
一条线段的中点

Being at neither one extreme nor the other; intermediate.
中部的，居中的：既不在一端，又不在另一端的；中间的

Intervening between an earlier and a later period of time; being an intermediate part of a sequence or series:
中期的；中间的：在早期和晚期的中间的；作为一系列或者一连串的中间部分的：
例句：
the middle years.
中年

Middle Geology Of or relating to a division of geologic time between an earlier and a later division:
Middle 【地质学】 中期的：属于或关于地质年代早期和晚期中间部分的：
例句：
the Middle Paleozoic.
中古生代的

Middle Of or relating to a stage in the development of a language or literature between earlier and later stages:
Middle 中古的：属于或关于语言或文学发展早期和晚期中间部分的：
例句：
Middle Swedish.
中古瑞典语

Grammar Of a verb form or voice in which the subject both performs and is affected by the action specified.
【语法】 中动态的：和动词形式或动词语态有关的，这个动词的主语既是行为主体，又受行为所影响
n.（名词）
An area or a point equidistant between extremes; a center:
当中，中央：离两端等距离的部分或点；中心：
例句：
the middle of a circle.
圆的中心

Something intermediate between extremes; a mean.
中部，中间，平均：两个极端的中间事物；中项
The interior portion:
内部：
例句：
the middle of a chain.
链条的内部

The middle part of the human body; the waist.
身体的中部；腰部
Logic A middle term.
【逻辑学】 中项
v.tr.（及物动词）
mid.dled,mid.dling,mid.dles
To place in the middle.
放在中间
Nautical To fold in the middle:
【航海】 把…对折：
例句：
middle the sail.
升半帆

来源：
Middle English middel
中古英语 middel
from Old English * see medhyo-
源自 古英语 *参见 medhyo-