Encyclopedias, Almanacs, Transcripts, and Maps
- death penalty
- deathwatch beetle
- Debt for Nature Swap
- Decapoda (Crabs, Shrimps, and Lobsters)
- Deciduous Forest
- Decline Spiral
- Decomposers
- Deep-Well Injection
- Defender of the Faith
- Defenders of Wildlife
- Deification
- Delaney Clause
- Delitzsch, Friedrich
- Deloria, Ella Cara
- Deltas
- Demeter and Persephone
- Demiéville, Paul
- Democratic Republican Party
- Demons: An Overview
- Demons: Psychological Perspectives