Prime Ideal
An Ideal 
such that if 
, then either 
or 
.
- Double Gamma Function
- Double Point
- Double Sixes
- Double Sum
- Doublet Function
- Doubly Even Number
- Doubly Magic Square
- Dougall-Ramanujan Identity
- Dougall's Theorem
- Doughnut
- Douglas-Neumann Theorem
- Dovetailing Problem
- Dowker Notation
- Down Arrow Notation
- Dozen
- Dragon Curve
- Dragon Fractal
- Draughts
- Drinfeld's Symmetric Space
- Droz-Farny Circles
- Drum
- D-Statistic
- D-Triangle
- Dual Basis
- Dual Bivector