1
on one's back
指仰卧姿势，背朝下。
He was lying on his back.
他仰面躺着。
背；背部；后背
先理解核心含义，再看它在真实句子里的用法。
背；背部；后背
The rear part of a human or animal body between the neck and the lower end of the spine.
He was lying on his back.
他仰面躺着。
背部
The rear of the body, especially the part between the neck and the end of the spine and opposite the chest and belly.
大而浅的桶；酿酒师、蒸馏师、染工、腌制商、制胶商等用来混合或冷却麦芽汁、盛水、盛热胶等的水池、桶或槽。
A large shallow vat; a cistern, tub, or trough, used by brewers, distillers, dyers, picklers, gluemakers, and others, for mixing or cooling wort, holding water, hot glue, etc.
人(或动物)身体从颈部到脊柱末端的后部
the posterior part of a human (or animal) body from the neck to the end of the spine
最远离前面的部分
That which is farthest away from the front.
My back hurts after sitting at the desk all day.
在桌子前坐了一整天后，我的背很疼。
AI contextual example
He carried his little daughter on his back through the park.
他背着小女儿穿过公园。
AI contextual example
She has a small mole on her lower back.
她的下背部有一颗小痣。
AI contextual example
his back was nicely tanned
他的背部晒得很好
WordNet
指仰卧姿势，背朝下。
He was lying on his back.
他仰面躺着。
There is a small garden at the back of the house.
房子后面有一个小花园。
常指物体的背面或后部。
He wrote his name on the back of the photo.
他把名字写在照片背面。
Not this
He is lying on back.
Use this
He is lying on his back.
英语中，谈及身体部位时通常需要物主代词（如my, his），而汉语常省略，导致遗漏。此处需用'his'来指明是'他的背部'。
Not this
Please write at the back of the paper.
Use this
Please write on the back of the paper.
'在纸的背面'应用介词'on'表示表面，而'at'用于地点或位置，所以需改为'on'。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
下背部
He felt a sharp pain in his lower back.
他感到下背部一阵剧痛。
背痛
Prolonged sitting can cause back pain.
久坐会导致背痛。
在…的后部；在…后面
The library is at the back of the campus.
图书馆在校园的后部。
后脑勺
She bumped the back of her head against the door.
她的后脑勺撞到了门上。
仰卧着（背朝下）
The patient had to lie on his back for hours.
病人不得不仰卧数小时。
手背
He wiped his forehead with the back of his hand.
他用手背擦了擦额头。
支持某人，罩着某人
Don't worry — I've got your back.
别担心——我支持你。
背着某人，在某人背后（暗中做某事）
He was talking about me behind my back.
他背着我说我的闲话。
赞扬，鼓励
She gave the children a pat on the back for their hard work.
她因为孩子们的努力而表扬了他们。
我罩着你。
This phrase, popularized by movies and TV shows, is used to express loyalty and willingness to support or protect someone in a difficult situation.
这个短语因电影和电视剧而广为流传，用来表达忠诚以及在困难情况下支持或保护某人的意愿。
Use back (adv.) naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
把 back 想成'背'：你背的书包正贴在后背(back)上，后背就是 back。
语域：neutral 常见场景：日常对话、医疗咨询、物体方位描述 作名词表示“背部”或“背面”时，通常属于中性常用词，日常口语和书面语中都自然；在医疗或方位描述里也比较常见，不需要刻意区分正式或非正式语气。
以上词都与 back 同韵，读音均为 /æk/，拼写为 -ack。注意形近异音词，如 bake /beɪk/ 和 bark /bɑːk/，拼写接近但发音与 back 不同。
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.