Subnormal
is a subnormal Subgroup of 
if there is a ``normal series'' (in the sense of Jordan-Holder) from to .
- d'Alembert's Theorem
- Damped Exponential Cosine Integral
- d-Analog
- Dandelin Spheres
- Danielson-Lanczos Lemma
- Darboux Integral
- Darboux-Stieltjes Integral
- Darboux Vector
- Darling's Products
- Dart
- Darwin-de Sitter Spheroid
- Darwin's Expansions
- Database
- Data Structure
- Daubechies Wavelet Filter
- Davenport-Schinzel Sequence
- Dawson's Integral
- Day of Week
- de Bruijn Constant
- de Bruijn Diagram
- de Bruijn Graph
- de Bruijn-Newman Constant
- de Bruijn Sequence
- de Bruijn's Theorem
- Debye Functions