Strategic Defense Initiative 
(abbreviation SDI)
A projected US system of defence against nuclear weapons, using satellites armed with lasers to intercept and destroy intercontinental ballistic missiles. The project was renamed the Ballistic Missile Defense Organization in 1993. Popularly known as Star Wars.
- depth of focus
- depth perception
- depth psychology
- depth sounder
- depublication
- depublish
- depurate
- depuration
- depurative
- depurator
- deputation
- depute
- deputise
- deputize
- deputy
- Deputy Lieutenant
- deputyship
- dequeue
- De Quincey, Thomas
- der
- deracinate
- deracination
- deradicalisation
- deradicalise
- deradicalization