A.D. actually means Anno Domini, which translates to "the Year of Our Lord". It refers to the division between BC (Before Christ) and AD as the major division of time reckoning in the majority of modern cultures. AD as "After Death" is not only erroneous (the time it refers to is when Jesus was traditionally born, not when he traditionally died), but comes from the misconception that because BC refers in English to "Before Christ", then AD must also refer to an English expression relating to Jesus, thus "After Death".