- the rear surface of the human body from the shoulders to the hips（人的）背; 背部：
he lay on his back
他仰面躺着
Forbes slapped me on the back
福布斯拍了一下我的背
as modifier back pain.背痛。
- the corresponding upper surface of an animal's body（动物的）背部。
- the spine of a person or animal（人或动物的）脊骨, 脊柱。
- the main structure of a ship's hull or an aircraft's fuselage船体; （飞机）机身。
- the part of a chair against which the sitter's back rests椅背。
- the part of a garment that covers a person's back（衣服的）背面。
- a person's torso or body regarded in terms of wearing clothes（人的）躯干; 身体（就着装而言）：
all he owned were the clothes on his back.
他除了身上的衣服之外一无所有。
- a person's back regarded as carrying a load or bearing an imposition（人的）背; 身体（就负重或承担不便而言）：
the Press are on my back.
出版社的担子落在了我身上。
- the side or part of something that is away from the spectator or from the direction in which it moves or faces; the rear背面, 反面; 后面：
at the back of the hotel is a secluded garden
酒店的后面是一个静僻的花园
the backs of four high buildings.
四幢大厦的背面。
- in sing. the position directly behind someone or something背后; 正后方：
she unbuttoned her dress from the back.
她从背后解开连衣裙纽扣。
- the side or part of an object opposed to the one that is normally seen or used; the less active, visible, or important part of something背面; 反面; 隐蔽面：
write on the back of a postcard.
写在明信片的背面。
- a player in a team game who plays in a defensive position behind the forwards（团队运动中的）卫。
the Backs
the grounds of Cambridge colleges which back on to the River Cam（背向剑河的）剑桥大学后园。
- towards the rear; in the opposite direction from the one that one is facing or travelling向后地：
she moved back a pace
她向后退了一步
she walked away without looking back.
她头也不回地走掉了。
- expressing movement of the body into a reclining position向后仰（或靠）地：
he leaned back in his chair
他身体向后仰坐在椅子里
sit back and relax.
靠着椅背坐, 放松。
- at a distance away在远处：
keep back from the roadside
远离路边
I thought you were miles back.
我原以为你在几英里远的地方。
back of
N. Amer. behind〈北美〉在后面：he knew that other people were back of him.
他知道其他人在他后面。
- N. Amer. losing by a specified margin〈北美〉（落）后：
the team was five points back.
这支队落后五分。
- used to express a return to an earlier or normal position or condition回到先前的位置（或状况）; 恢复正常：
she put the book back on the shelf
她把书放回书架上
drive to Montreal and back
开车去蒙特利尔又开回来
I went back to sleep
我又睡着了
he was given his job back
他复职了
things were back to normal.
一切恢复了正常。
- at a place previously left or mentioned在原处：
the folks back home are counting on him.
家乡的人们现在都指望他了。
- fashionable again再度流行：
sideburns are back.
短连鬓胡子再度流行起来。
- in or into the past在过去; 回到过去：
he made his fortune back in 1955.
早在1955年他就发了财。
- in return作为答复（或回报）：
they wrote back to me.
他们给我回了信。
- with obj. give financial, material, or moral support to（经济、物质或道德上）支持：
he had a newspaper empire backing him
他有一个报纸王国在支持他
go up there and tell them - I'll back you up.
去那儿告诉他们, 我会支持你。
- bet money on (a person or animal) winning a race or contest赌（参加比赛的人或动物）赢：
he backed the horse at 33-1.
他以33赔1赌那匹马赢。
- be in favour of赞成, 赞同：
the Borough Council backs the scheme.
市镇议会赞成这计划。
- supplement in order to reinforce or strengthen增援（以加强）：
US troops were backed up by forces from European countries.
美国部队得到了欧洲国家部队的增援。
- with obj.（常作be backed）cover the back of (an article)in order to support, protect, or decorate it给…装背衬：
a mirror backed with tortoiseshell.
以玳瑁作背衬的镜子。
- (especially in popular music) provide musical accompaniment to (a singer or musician)（尤指流行音乐中）为（歌手, 音乐家）伴奏：
on his new album he is backed by an American group.
他的这张专辑由一支美国乐队担任伴奏。
- put a song or piece of music on the less important side of (a recording)收录在（录制品）的次要面; 附带收录进（录制品）：
the new single is backed with a track from the LP.
这张新单曲里附带收录了LP唱片里的一首歌。
- no obj., with adverbial of direction walk or drive backwards倒车; 后退：
she tried to back away
她想要朝后退
figurative 〈喻〉the government backed away from the plan
政府退出了那个计划
with obj. he backed the Mercedes into the yard.他把那辆梅塞德斯车倒进院子里。
- no obj.(of the wind) change direction anticlockwise around the points of the compass（风）逆时针转向：
the wind had backed to the north-west.
风向逆时针转为西北。 VEER1的反义词。
- with obj. Sailing put (a sail) aback in order to slow the vessel down or assist in turning through the wind【航海】收（帆）。
- no obj.
back on/on to
(of a building or other structure) have its back or rear facing or adjacent to（建筑物等）背对着; 背连着： his garage wall backs on to the neighbouring property.
他车库的墙背连着邻居家。
- with obj.（一般作 be backed）lie behind or at the back of在…后面：
the promenade is backed by lots of cafes.
在海滨人行道后面有很多咖啡馆。
- of or at the back of something（在）后面的：
the back garden
后（花）园
the back pocket of his jeans.
他牛仔裤的后袋。
- situated in a remote subsidiary position边远的; 偏僻的：
back roads.
偏僻的小路。
- (especially of wages or something published or released) from or relating to the past（尤指薪水、出版物或发行物）过去的：
the band's back catalogue
乐队以前的曲目
she was owed back pay.
她被拖欠薪水。
- directed towards the rear or in a reversed course向后的; 相反的：
a back header.
一个头球回传。
- Phonetics (of a sound) articulated at the back of the mouth【语音】（音）后位的; 舌后的。
at someone's back
- in pursuit or support someone追求; 支持（某人）。
back and forth
- to and fro来回地。
back in the day
- in the past; some time ago在过去, 在以前：
back in the day, he'd had one of the greatest minds I'd ever come across.
从前他曾是我所遇到过的最有头脑的人之一。
someone's back is turned
- someone's attention is elsewhere某人的注意力在别处：
he kissed her quickly, when the landlady's back was turned.
趁女房东注意别的地方的时候, 他很快地吻了她一下。
the back of beyond
- a very remote or inaccessible place偏僻处。
back o'Bourke
- Austral. informal the outback〈澳, 非正式〉内地。
- ORIGIN: from the name of a town in north-west New South Wales.
the back of one's mind
- used to express that something is in one's mind but is not consciously thought of or remembered下意识：
she had a little nagging worry at the back her mind.
下意识里她还存有顾虑。
back to front
- Brit. with the back at the front and the front at the back〈英〉前后颠倒：
the exhausts had been fitted back to front
排气管前后装倒了
a back-to-front baseball cap.
前后颠倒的棒球帽。
back water
- reverse the action of the oars, causing a boat to slow down or stop倒桨。
back the wrong horse
- make a wrong or inappropriate choice下错了赌注; 做错了选择。
behind someone's back
- without a person's knowledge and in an unfair or dishonourable way在某人背后, 背着某人：
Carla made fun of him behind his back.
卡拉在他背后取笑他。
get（或 put）someone's back up
- make someone annoyed or angry惹恼（或惹怒）某人。
in back
- N. Amer. at the back of something, especially a building〈北美〉在后面（尤指在建筑物的后面）：
dad demolished an old shed in back of his barn.
父亲拆掉了仓库后面的一个旧棚。
know something like the back of one's hand
- be entirely familiar with a place or route对（某地或路线）了如指掌。
on one's back
- in bed recovering from an injury or illness卧床休养。
put one's back into
- approach (a task) with vigour竭尽全力于。
turn one's back on
- ignore (someone) by turning away from them对（某人）掉头不管; 轻视（某人）。
- reject or abandon (a person or thing that one was previously involved with)否认; 抛弃。
with one's back to（或 up against）the wall
- in a desperate situation; hard-pressed走投无路; 处于绝境。
back down
- withdraw a claim or assertion in the face of opposition（遭遇反对时）收回声明（或宣言）：
the contenders backed down from their original pledge.
竞选人纷纷取消了原先的誓言。
back off
- draw back from action or confrontation撤退：
they backed off from fundamental reform of the system.
他们退出了基本的体制改革。
- another way of saying back down.同back down.
back out
- withdraw from a commitment退出：
if he backs out of the deal they'll sue him.
如果他退出这笔交易, 他们就会起诉他。
back up
- (of vehicles) form into a queue due to congestion（车辆）堵塞：
the traffic began to back up.
交通开始堵塞。
- (of running water) accumulate behind an obstruction（流水）积聚。
back something up
- Computing make a spare copy of data or disk【计算机】为…备份。
- （一般作be backed up）cause vehicles to form into a queue due to congestion使（车辆）堵塞：
the traffic was backed up a couple of miles in each direction.
各方向的车辆都堵了数英里。