AD means
Anno Domini, which means 'in the year of Our Lord' in Latin.
(
In Latin, the word
'anno' includes
'in the')
A.D. stands for "anno domini," Latin for "year of the Lord." It is theoretically based on the time of the birth of Jesus, though it may be off by a few years.
Many people are beginning to use C.E. ("Christian Era") instead of A.D., and also B.C.E ("Before Christian Era") instead of B.C. ("Before Christ").
Answer
AD is an acronym for the Latin term
anno Domini, meaning the year (
anno) of the Lord (D
omini). It is now becoming common to use the alternative acronym
CE, which means Common Era or Christian Era.
Anno Domini (latin) meaning in the year of our lord
AD - stands for
Anno Domini, which is Latin for
in the year of Our Lord - in other words after the birth of Christ.
As a chronological designation it was invented by Dionysius Exiguus in 525 A.D. to Christianize the study and presentation of history by orienting every event to the birth of Christ. So events before Christ was born are called B.C. and those after his birth are called A.D.