Daddy of all
Very much.

Dark horse
A Person with unknown background or profile.

Davy Jones' locker
Very deep in the sea. At the bottom of the sea

Daylight robbery
An ironic term when a shop sells you something very expensive.

Dead duck
A victim or a totally cannot survive situation.

Die away            
Can't speak / talk (for any reasons)

Different strok for different folks
Everyone has different interest and tastes

Do someone injury
Succeed

Do the sights of
Curse someone / something

Dog eat dog
A dirty competition. No rule, no manner

Down at heel
Very old. something too old to repair

Draw a line
Take a risk / Take a chance to try

Dressed to kill
Wear one's finest clothing

Dress to the teeth
Dress elegantly

Drive someone up a wall
Annoy someone greatly

Drop someone a line
Call somone

Duck soup
Finish with almost no effort

Dwell on
Think too much / repeatly think or do something