- Attention Deficit Disorder, see also :w:Attention-Deficit_Hyperactivity_Disorder, article about ADD in Wikipedia
- Accidental Death and Dismemberment
- A designation on prerecorded compact discs indicating that the contents were recorded in analog but mixed and mastered in digital; compare AAD, DAD, DDD.
proper noun (wikipedia, Angles)
- A member of an ancient Germanic tribe, one of several which invaded Britain and merged to become the Anglo-Saxons.