D

Idiom Starting With D

Dark Horse: 

One who was previously unknown and is now prominent.

Dead Ringer: 

100% identical. A duplicate.

Devil's Advocate: 

Someone who takes a position for the sake of argument without believing in that particular side of the arguement. It can also mean one who presents a counter argument for a position they do believe in, to another debater.

Dog Days of Summer: 

The hottest days of the summer season.

Don't count your chickens before they hatch: 

Don't rely on it until your sure of it.

Don't Look A Gift Horse In The Mouth: 

When someone gives you a gift, don't be ungrateful.

Don't Put All Your Eggs In One Basket: 

Do not put all your resources in one possibility.

Doozy: 

Something outstanding.

Down To The Wire: 

Something that ends at the last minute or last few seconds.

Drastic Times Call For Drastic Measures: 

When you are extremely desperate you need to take extremely desperate actions.

Drink like a fish: 

To drink very heavily.

Drive someone up the wall: 

To irritate and/or annoy very much.

Dropping Like Flies: 

A large number of people either falling ill or dying.

Dry Run: 

Rehearsal.