| Idiom | Meaning | Example |
| a daredevil | a daring person, bodacious, take a chance | What a daredevil! She jumped across a ten-foot chasm! |
| a dead giveaway | a clear signal, an obvious sign | The smile on her face was a dead giveaway that she got the job. |
| a dead heat | a race that finishes in a tie for first, dead even | A photograph of the finish line proved that it was a dead heat. |
| a dead loss | a complete loss, a write-off (see write it off) | The spoiled meat was a dead loss. We couldn't eat any of it. |
| a dead ringer | a very close likeness, like a twin | Chad is a dead ringer for Mel Gibson. They look like twins. |
| a dickens of a time | a difficult task, a task with problems, a hell of a time | After the car slid in the ditch we had a dickens of a time getting it back on the road. |
| a different kettle of fish | different, not the same | A cult is not a religion. A cult is a different kettle of fish entirely. |
| a dildo [B] | a manufactured penis, a vibrator shaped like a penis | "When Ed's away I use a dildo." "Oh. That's interesting." |
| a dime a dozen | very cheap, low priced, dirt cheap | He can remember when eggs were cheap - a dime a dozen. |
| a dog's age | a long time, 10-15 years, a coon's age | Mel! I haven't seen you for a dog's age - at least ten years! |