or A.D.

in the year of the Lord; since Christ was born: Charlemagne was born in a.d. 742.

Words nearby a.d.

Origin of a.d.

From the Latin word annō Dominī

usage note for a.d.

Because anno Domini means “in the year of the Lord,” its abbreviation a.d. was originally placed before rather than after a date: The Roman conquest of Britain began in a.d. 43 (or began a.d. 43). In edited writing, it is still usually placed before the date. But, by analogy with the position of b.c. “before Christ,” which always appears after a date ( Caesar was assassinated in 44 b.c. ), a.d. is also frequently found after the date in all types of writing, including historical works: The Roman emperor Claudius I lived from 10 b.c. to 54 a.d. Despite its literal meaning, a.d. is also used to designate centuries, being placed after the specified century: the second century a.d.

Definition for a.d. (2 of 4)


before the day.

Origin of a.d.

From the Latin word ante diem

Definition for a.d. (3 of 4)


after date.
autograph document.

Definition for a.d. (4 of 4)


active duty.
art director.
assembly district.
assistant director.
athletic director.
average deviation.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Cultural definitions for a.d.


An abbreviation used with a date, indicating how many years have passed since the birth of Jesus. The abbreviation may appear before the date (a.d. 1988), or it may appear after the date (1988 a.d.). It stands for anno Domini, a Latin phrase meaning “in the year of our Lord.” (Compare b.c.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.