(Homonym: add).
A public promotion of some product or service; SYN. advertisement, advertising, advert.

1. To; toward — usually ac- before c, k, or q and af- before f and ag- before g and al- before l and ap- before p and as- before s and at- before t and ad- before other sounds but sometimes ad- even before one of the listed consonants
2. Near; adjacent to

In the Christian chronological system, abbreviation for anno Domini.
Anno domini

Andorra.

1 active duty.
2 after date.
3 Alzheimer's disease.
4 anno Domini — often printed in small capitals and often punctuated.
5 assembly district.
6 assistant director.
7 athletic director.

Anno Domini (in the year of Our Lord); used in reckoning dates after the supposed year Christ was born.