Do time

(UK) When someone is doing time, they are in prison.

Do's and don't's

The do's and don't's are what is acceptable or allowed or not within an area or issue, etc.

Dodge the bullet

If someone has dodged a bullet, they have successfully avoided a very serious problem.

Does a one-legged duck swim in circles?

(USA) (US Southern) This is a response given to an unnecessary question for which the obvious answer is yes. Example: If you were to ask an Olympic archer whether she could put an arrow in an apple at ten yards, she could answer: "Does a one-legged duck swim in circles?"('Do one-legged ducks swim in circles?' is also used.)

Dog and pony show

(USA) A dog and pony show is a presentation or some marketing that has lots of style, but no real content.

Dog days

Dog days are very hot summer days.

Dog eat dog

In a dog eat dog world, there is intense competition and rivalry, where everybody thinks only of himself or herself.

Dog in the manger

(UK) If someone acts like a dog in the manger, they don't want other people to have or enjoy things that are useless to them.

Dog tired

If you are dog tired, you are exhausted.

Dog's dinner

Something that is a dog's dinner is a real mess.

Dog's life

If some has a dog's life, they have a very unfortunate and wretched life.

Dog-eared

If a book is dog-eared, it is in bad condition, with torn pages, etc.

Dog-whistle politics

(AU) When political parties have policies that will appeal to racists while not being overtly racist, they are indulging in dog-whistle politics.

Doggy bag

If you ask for a doggy bag in a restaurant, they will pack the food you haven't eaten for you to take home.

Doldrums

If a person is in the doldrums, they are depressed. If a project or something similar is in the doldrums, it isn't making any progress.

Dollars for doughnuts

(USA) If something is dollars for doughnuts, it is a sure bet or certainty.

Don't bite the hand that feeds

When someone says this to you, they are trying to tell you not to act against those on whom you depend.

Don't catch your chickens before they're hatched

This means that you should wait until you know whether something has produced the results you desire, rather than acting beforehand. ('Don't count your chickens until they've hatched' is an alternative.)

Don't cry over spilt milk

When something bad happens and nothing can be done to help it people say, 'Don't cry over spilt milk'.

Don't give up the day job

This idiom is used a way of telling something that they do something badly.

Don't hold your breath

If you are told not to hold your breath, it means that you shouldn't have high expectations about something.

Don't judge a book by the cover

This idiom means that you should not judge something or someone by appearances, but should look deeper at what is inside and more important.

Don't know whether to wind a watch or bark at the moon

If you don't know what to do, you don't know whether to wind a watch or bark at the moon.

Don't look a gift horse in the mouth

This means that if you are given something, a present or a chance, you should not waste it by being too critical or examining it too closely.

Don't mention the war

This means that you shouldn't speak about things that could cause an argument or tension.This idiom was used in a classic episode of the much-loved British comedy series Fawlty Towers. As a consequence if you use this phrase in Britain, listeners will understand you to be referring to Germans, or just start laughing.

Don't push my buttons!

This can be said to someone who is starting to annoy you.

Don't shoot the messenger

This phrase can be used when breaking some bad news to someone and you don't want to be blamed for the news. ('Don't kill the messenger' is also used.)

Don't stand there with curlers in your hair

This means 'don't keep me waiting'. It's said to someone who is taking too long to get moving.

Don't stop and kick at every dog that barks at you

(USA) If we stop to kick at every dog that barks at us we will never arrive at our destination in life, because we are obsessed with righting insignifigant wrongs that should have no more effect on us then a dog that barks as we walk by.

Don't sweat the small stuff

(USA) This is used to tell people not to worry about trivial or unimportant issues.

Don't take any wooden nickels

(USA) This idiom is used to advise people not to be cheated or ripped off.

Don't throw bricks when you live in a glass house

Don't call others out on actions that you, yourself do. Don't be a hypocrite.

Don't trouble trouble until trouble troubles you

Don't go looking for trouble or problems- let them come to you.

Don't upset the applecart

If you are advised not to upset the applecart, you are being told not to disturb the way things are done because it might ruin things.

Don't wash your dirty laundry in public

(UK) People, especially couples, who argue in front of others or involve others in their personal problems and crises, are said to be washing their dirty laundry in public; making public things that are best left private. (In American English, 'don't air your dirty laundry in public' is used.)

Done to death

If a joke or story has been done to death, it has been told so often that it has stopped being funny.

Donkey work

Donkey work is any hard, boring work or task.

Donkey's years

This idiom means 'a very long time'.

Doormat

A person who doesn't stand up for themselves and gets treated badly is a doormat.

Dot all the i's and cross all the t's

If you dot all the i's and cross all the t's, you do something very carefully and thoroughly.

Double Dutch

(UK) If something is double Dutch, it is completely incomprehensible.

Double take

If someone does a double take, they react very slowly to something to show how shocked or surprised they are.

Double whammy

A double whammy is when something causes two problems at the same time, or when two setbacks occur at the same time.

Double-edged sword

If someone uses an argument that could both help them and harm them, then they are using a double-edged sword sword; it cuts both ways.

Doubting Thomas

A Doubting Thomas is someone who only believes what they see themselves, not what they are told.

Down and dirty

Down and dirty means unscrupulous and very competitive.

Down and out

If someone is down and out, they are desperately poor and need help.

Down at heel

Someone who is down at heel is short of money. ('Down in heel' is used in American English)

Down for the count

If someone is down for the count, they have lost a struggle, like a boxer who has been knocked out.

Down in the doldrums

If somebody's down in the doldrums, they are depressed and lacking energy.

Down in the dumps

If someone's down in the dumps, they are depressed.

Down in the mouth

If someone is down in the mouth, they look unhappy or depressed.

Down the drain

If something goes down the drain, especially money or work, it is wasted or produces no results.

Down the hatch

This idiom can be said before drinking alcohol in company.

Down the pan

If something has gone down the pan, it has failed or been ruined.

Down the pike

Something that is down the pike it is in the future.

Down the Swanee

If a plan or scheme, etc, goes down the Swanee, it goes wrong or fails.

Down the tubes

If something has gone down the tubes, it has failed or been ruined.

Down to the wire

(USA) If something goes down to the wire, like a competition, then it goes to the very last moment before it is clear who has won.

Down-to-earth

Someone who's down-to-earth is practical and realistic. It can also be used for things like ideas.