| DA | Duckling.Lang, Duckling.Core |
| Dataset | Duckling.Ranking.Types |
| Datetime | Duckling.Testing.Types |
| datetime | Duckling.Time.Corpus |
| datetimeInterval | Duckling.Time.Corpus |
| datetimeOpenInterval | Duckling.Time.Corpus |
| Datum | Duckling.Ranking.Types |
| Day | Duckling.TimeGrain.Types |
| dayOfMonth | Duckling.Time.Helpers |
| DayOfWeek | Duckling.Time.Types |
| dayOfWeek | Duckling.Time.Helpers |
| daysOfWeekOfMonth | Duckling.Time.Helpers |
| DE | Duckling.Lang, Duckling.Core |
| debug | Duckling.Debug |
| debugContext | Duckling.Debug |
| decimalsToDouble | Duckling.Numeral.Helpers |
| Degree | Duckling.Temperature.Types |
| dim | Duckling.Types, Duckling.Core |
| Dimension | Duckling.Dimensions.Types, Duckling.Core |
| dimension | Duckling.Types |
| direction | Duckling.Time.Types |
| Dish | Duckling.Quantity.Types |
| Distance | Duckling.Dimensions.Types, Duckling.Core |
| distance | Duckling.Distance.Helpers |
| DistanceData | |
| 1 (Type/Class) | Duckling.Distance.Types |
| 2 (Data Constructor) | Duckling.Distance.Types |
| DistanceValue | |
| 1 (Type/Class) | Duckling.Distance.Types |
| 2 (Data Constructor) | Duckling.Distance.Types |
| divide | Duckling.Numeral.Helpers |
| Document | Duckling.Types.Document |
| Dollar | Duckling.AmountOfMoney.Types |
| domain | Duckling.Url.Types |
| double | Duckling.Numeral.Helpers |
| dt | Duckling.Testing.Types |
| DucklingTime | |
| 1 (Type/Class) | Duckling.Resolve |
| 2 (Data Constructor) | Duckling.Resolve |
| Duration | Duckling.Dimensions.Types, Duckling.Core |
| duration | Duckling.Duration.Helpers |
| durationAfter | Duckling.Time.Helpers |
| durationAgo | Duckling.Time.Helpers |
| durationBefore | Duckling.Time.Helpers |
| DurationData | |
| 1 (Type/Class) | Duckling.Duration.Types |
| 2 (Data Constructor) | Duckling.Duration.Types |