A downstem that diffuses smoke through holes or slits before it enters the water chamber, cooling the smoke and making hits smoother.
- Dab mat
- Dab rig
- Dabber
- Dabbing
- Dank
- Decarboxylation
- Decriminalize
- Deep water culture
- Defoliation
- Delivery
- Delta-10
- Delta-8
- Dewaxing
- Diamond mining
- Diamonds
- Diesel
- Diffused downstem
- Diffuser
- Diffusion
- Directional airflow
- Directional flow
- Disc perc
- Dispensary
- Distillate
- Distributor
- Dogwalker
- Dome
- Domeless nail
- Dope
- Dose
- Downstem
- Dry sift
- Dugout