- with obj. and infinitive not prevent or forbid; allow允许, 让：
my boss let me leave early
我老板允许我早些下班
you mustn't let yourself get so involved.
你不可以让自己陷得太深。
- with obj. and adverbial of direction allow to pass in a particular direction使通过：
could you let the dog out?
把狗放出去好吗？
a tiny window that let in hardly any light.
几乎透不进光的小窗户。
- with obj. and infinitive used in the imperative to formulate various expressions［用在祈使句中表达多种意思］：
- （let us 或 let's）used as a polite way of making or responding to a suggestion, giving an instruction, or introducing a remark［用以礼貌地提出或回应建议或礼貌地命令或引出一句话］ 让我们…吧：
let's have a drink
我们来喝一杯吧
'Shall we go?'. 'Yes, let's.'
“咱们是不是该走了？”“好, 走吧。”
- （let me 或 let us）used to make a polite offer of help［礼貌地表示愿提供帮助］让我（或我们）…（好吗？）：
'Here, let me, ' offered Bruce.
“来, 让我来吧,"布鲁斯主动说道。
- used to express one's strong desire for something to happen or be the case［表示很希望某事能发生或就是那种情况］要是…多好啊, 但愿：
'Dear God, ' Jessica prayed, 'let him be all right.'
“慈爱的上帝," 杰西卡祷告说, “但愿他平安无事。”
- used as a way of expressing defiance or challenge表示藐视或挑战：
if he wants to walk out, well let him!
他要是想不干, 就让他走！
- used to express an assumption upon which a theory or calculation is to be based［用于提出作为某种理论或计算方法基础的臆断］假设, 设：
let A and B stand for X and Y respectively.
假设A与B分别代表X和Y。
- with obj. allow someone to have the use of (a room or property) in return for regular payments出租（房屋或土地）：
homeowners will be able to let rooms to lodgers without having to pay tax
业主将可以出租房屋而不必纳税
they've let out their flat.
他们已经把自己的公寓租出去了。
- award (a contract for a particular project) to an applicant（将工程）承包给某一竞标者：
preliminary contracts were let and tunnelling work started.
初步承包合同签好后隧道开挖工程随即开始。
- Brit. a period during which a room or property is rented to someone〈英〉租期：
I've taken a month's let on the flat.
那公寓我已承租一个月。
- a property available for rent待租房, 可出租房产：
an unfurnished let.
不含家具的待租房。
let alone
- used to indicate that something is far less likely, possible, or suitable than something else already mentioned［表示某事比刚提到的更不可能或更不恰当］更别提：
he was incapable of leading a bowling team, let alone a country.
他连带领保龄球队的本事都没有, 更别提领导一个国家了。
let someone/thing alone
- 见ALONE.
let someone/thing be
- stop disturbing or interfering with别打扰, 不干预：
let him be - he knows what he wants.
随他去吧——他知道自己需要什么。
let someone down gently
- seek to give someone bad news in a way that avoids causing them too much distress or humiliation婉转地告知（以减轻对方的痛苦或羞耻感）。
let something drop（或 fall）
- casually reveal a piece of information无意中说出某事, 不经意地透露某事：
from the things he let drop I think there was a woman in his life.
从他随口说出的话里, 我听出他身边有一个女人。
let fall
- Geometry draw (a perpendicular) from an outside point to a line【几何】向一直线作垂线。
let fly
- attack, either physically or verbally对…进行（身体或语言）攻击：
the troops let fly with shells loaded with chemical weapons.
军队用化学毒剂炮弹进行攻击。
let oneself go
- act in an unrestrained or uninhibited way无拘无束地行事, 率性而为：
you need to unwind and let yourself go.
你该放松下来, 随心所欲地去做你自己的事情。
- become careless or untidy in one's habits or appearance（让自己在日常行为方面）变得随随便便; （让自己）变得不修边幅：
he's really let himself go since my mother died.
自从妈妈去世之后, 他变得不修边幅了。
let someone/thing go
- allow someone or something to escape or go free放, 释放：
they let the hostages go.
他们释放了人质。
- dismiss an employee解雇员工。
- （亦作let go 或 let go of）relinquish one's grip on someone or something松手, 放开, 释放：
Adam let go of the reins
亚当脱手缰绳
figurative 〈喻〉you must let the past go.
你必须摆脱过去。
let someone have it
- informal attack someone physically or verbally〈非正式〉揍, 教训; 痛骂：
I really let him have it for worrying me so much.
他老让我犯愁, 我狠狠教训了他一顿。
let in（或 out） the clutch
- engage (or release) the clutch of a vehicle by releasing pressure on (or applying it to) the clutch pedal松开（或踩下）汽车等的离合器踏板使其起啮合作用（或松开啮合）。
let it drop（或 rest）
- say or do no more about a matter or problem到此为止。
let it go（或 pass）
- choose not to react to an action or remark不搭理：
the decision worried us, but we let it go.
这决定让我们担心, 不过我们没去理它。
let someone know
- inform someone告诉某人：
let me know what you think of him.
告诉我你怎么看他。
let someone/thing loose
- release someone or something放开（某人或某物）：
let the dog loose for a minute.
把狗放开一会儿吧。
- allow someone freedom of action in a particular place or situation允许某人（在某一地点或场合）自由行动：
people are only let loose on the system once they have received sufficient training.
只有在接受足够训练之后, 人们才能在该系统内自由行动。
- suddenly utter a sound or remark突然说出：
he let loose a stream of abuse.
他突然破口大骂。
let me see（或 think）
- used when one is pausing, trying to remember something, or considering one's next words用于因一时想不起某事而说话停顿时让我想想：
now let me see, where did I put it?
让我想想, 我把它放哪儿了？
let me tell you
- used to emphasize a statement［表示强调］告诉你吧：
let me tell you, I was very scared!
告诉你吧, 我当时吓坏了。
let off steam
- 见STEAM.
let rip
- 见
RIP1 .
let's face it（或 let's be honest）
- informal used to convey that one must be realistic about an unwelcome fact or situation〈非正式〉［表示应面对现实］老实说, 说实在的：
let's be honest, your taste in men is famously bad.
老实说, 你看男人的眼光简直差极了。
let slip
- 见
SLIP1 .
let's pretend
- a game or set of circumstances in which one behaves as though a fictional or unreal situation is a real one“假扮真”游戏; 以假作真态势（指人的行为表现有意无意地把虚构或不真实的情况当作真实的情况这样一种事态）。
let's say（或 let us say）
- used as a way of introducing a hypothetical or possible situation［引出假设或可能情况］比方说：
let's say we agreed to go our separate ways.
比方说我们同意分道扬镳。
to let
- (of a room or property) available for rent（房屋）可供出租的。
let down
- (of an aircraft or a pilot) descend prior to making a landing（飞机或飞行员在准备着陆前）下降。
let someone down
- fail to support or help someone as they had hoped or expected（在某人希望得到帮助时）不予理会。
-
let someone/thing down
have a detrimental effect on the overall quality or success of someone or something使功亏一篑, 影响大局： the whole machine is let down by the tacky keyboard.
整个机器就被这个破键盘给搞坏了。
let something down
- lower something slowly or in stages慢慢放下, 放低：
they let down a basket on a chain.
他们用链子把篮子放了下去。
- make a garment longer by lowering the hem放出（褶边）, 放长（衣服）。
- Brit. deflate a tyre〈英〉给车胎放气。
let oneself in for
- informal involve oneself in (something likely to be difficult or unpleasant)〈非正式〉陷入, 卷入（麻烦）：
I didn't know what I was letting myself in for.
我不知道自己会卷入什么样的麻烦之中。
let someone in on/into
- allow someone to know or share (something secret or confidential)让（某人）知道（内情）：
I'll let you into a secret.
我告诉你一个秘密。
let something into
- set something back into (the surface to which it is fixed), so that it does not project from it把…嵌入, 插入：
the basin is partly let into the wall.
洗手盆部分嵌入墙内。
let someone off
- punish someone lightly or not at all for a misdemeanour or offence（对错误或非法行为）从轻处理, 放过：
he was let off with a caution.
他被从轻发落, 受了警告就没事了。
- excuse someone from a task or obligation允许不必（工作）：
he let me off work for the day.
他允许我这天不干活。
let something off
- cause a gun, firework, or bomb to fire or explode放（枪, 爆竹）; 引爆（炸弹）。
let on
- reveal or divulge information to someone放口风, 透露内情：
she knows a lot more than she lets on
她知道的比透露出来的要多得多
with clause I never let on that he made me feel anxious.我从未告诉别人他让我担心的秘密。
- pretend假装：
with clause they all let on they didn't hear me.他们都假装没听见我的话。
let out
- N. Amer. (of lessons at school, a meeting, or an entertainment) finish, so that those attending are able to leave〈北美〉（课程, 会议, 娱乐）结束：
his classes let out at noon.
他的课中午结束。
let someone out
- release someone from obligation or suspicion不再让（某人）负责, 不再猜疑（某人）：
they've started looking for motives - that lets me out.
他们已经开始寻找动机了——我的嫌疑也因此被排除了。
let something out
- utter a sound or cry发出声音或喊叫：
he let out a sigh of happiness.
他愉快地舒了口气。
- make a garment looser or larger, typically by adjusting a seam（尤指改缝）放大（衣服）。
- reveal a piece of information透露消息：
with clause she let out that he'd given her a lift home.她透露说他开车送她回家。
let up
- informal (of something undesirable) become less intense or severe〈非正式〉（不快之事）减小, 缓和：
the rain's letting up - it'll be clear soon.
雨越下越小, 马上就会放晴。
- relax one's efforts放松努力：
she was so far ahead that she could afford to let up a bit.
她遥遥领先, 所以她可以稍微放松一点。
let up on
- informal treat or deal with in a more lenient manner〈非正式〉宽容对待, 放…一马：
she didn't let up on Cunningham.
她没有放坎宁安一马。
- (in racket sports) a circumstance under which a service is nullified and has to be taken again, especially (in tennis) when the ball clips the top of the net and falls within bounds（网球、乒乓球、羽毛球等使用球拍和球网运动用语）触网重发（球）。
- archaic hinder〈古〉妨碍, 阻碍：
pray you let us not; we fain would greet our mother.
莫阻吾辈, 吾唯愿致意母亲。
let or hindrance
- formal obstruction or impediment〈正式〉妨碍, 阻碍：
the passport opened frontiers to the traveller without let or hindrance.
这一护照使旅行者可以无阻碍地入境。
play a let
- (in tennis, squash, etc.) play a point again because the ball or one of the players has been obstructed（网球等运动）触网重发。