Common Nouns:
* Day
* Dog
* Door
* Dream
* Dress
* Drink
* Dust
* Dinner
* Dance
* Desk
* Diamond
* Doctor
* Dollar
* Dragon
* Drum
* Driver
* Drop
* Duck
* Dinosaur
* Dish
* Decision
* Design
* Detail
* Direction
* Distance
* Discovery
Less Common Nouns:
* Dais
* Dacha
* Daemon
* Daggers
* Dairy
* Dally
* Dam
* Dart
* Datum
* Dawn
* Debris
* Debt
* Decade
* Deception
* Defiance
* Degree
* Deluge
* Demise
* Depot
* Derby
* Desert
* Destiny
* Dialogue
* Diploma
* Discontent
* Disease
* Disguise
* Diver
* Docket
* Dome
* Don
* Donut
* Draft
* Drama
* Dread
* Dream
* Drone
* Duel
* Dungeon
* Dynamo
Abstract Nouns:
* Danger
* Darkness
* Death
* Democracy
* Desire
* Destiny
* Doubt
* Duty
* Discipline
* Disappointment
* Diversity
This is just a small sample, and there are many more nouns that start with "D"!