China 
Africa 
- Deionized water
- Delafossite
- Delamination
- Delaunay triangulation
- Delay
- Delay calculation
- Delay differential equation
- Delay lines
- Delay spread
- Delay-tolerant networking
- Delayed extraction
- Delayed neutrons
- Delayed puberty
- Delegates
- Delegation
- Deletions
- Delftia tsuruhatensis
- Deliberative agent
- Delimiters
- Delirium
- Delivery robot
- Dell Optiplex
- Delocalized
- Delphi
- Delphi method
- Delta encoding
- Delta method
- Delta modulation
- Delta rule
- Delta waves
- Delta wings
- Delta-aminolevulinic acid dehydratase
- Delta-sigma modulation
- Delta-wye transformer
- Deltahedra
- Deltamethrin
- Deltas
- Deltoid ligament
- Deltoid muscle
- Demand characteristics
- Demand controlled ventilation
- Demand factor
- Demand paging
- Demand response
- Demand signal
- Demand-controlled ventilation
- Dematerialisation
- Dematerialization
- Dementia
- Dementia with Lewy bodies
- Demes
- Demethylase
- Demethylation
- Demeton-s-methyl
- Demineralized bone matrix
- Demister
- Demodulation
- Demographic
- Demographic profile
- Demography
- Demolition
- Demolition waste
- Demosaicing
- Demulsifiers
- Demurrage
- Denaturant
- Denaturation
- Dendrimers
- Dendritic
- Dendritic cells
- Dendritic spines
- Dendronized polymers
- Dengue fever
- Dengue virus
- Denier
- Denileukin diftitox
- Denim
- Denitrification
- Denitrifying bacteria
- Dennard scaling
- Denosumab
- Denotational semantics
- Dense breast tissue
- Dense connective tissue
- Dense granules
- Dense plasma focus
- Densely defined operator
- Densitometry
- Density
- Density altitude
- Density estimation
- Density gradient
- Density gradient centrifugation
- Density logging
- Density matrix
- Density of air
- Density of states
- Dental abscess
- Dental arch
- Dental caries
- Dental composite
- Dental erosion
- Dental fluorosis
- Dental implants
- Dental plaque
- Dental porcelain
- Dental prostheses
- Dental pulp stem cells
- Dental trauma
- Dentate gyrus
- Denticity
- Dentin
- Dentin hypersensitivity
- Dentinal tubules
- Denudation
- Denver Basin
- Deontic logic
- Deoxidization
- Deoxidizer
- Deoxyadenosine
- Deoxycholic acid
- Deoxycytidine
- Deoxygenation
- Deoxyguanosine
- Deoxyribonuclease
- Deoxyribonucleotides
- Deoxyribozymes
- Departmentalization
- Departure function
- Dependability
- Dependencies
- Dependency
- Dependency graph
- Dependent sources
- Dephasing
- Dephosphorylation
- Depleted uranium
- Depletion force
- Depletion gilding
- Depletion region
- Deployment
- Depolarization
- Depolarization ratio
- Depolarizer
- Depolymerization
- Deposit-refund system
- Deposition
- Depreciation
- Depressants
- Depressions