Definition of "AD"

Founded AO.DI. 1728 by Benj. Franklin

1916 September 23, The Saturday Evening Post, volume 189, number 13, page 3

There is a striving towards naturalism in agricultural scenes painted on bricks in tombs of the third century AD recently excavated at Chia-yü-kuan in Kansu Province which is reminiscent of later European illuminated manuscripts such as the English fifteenth-century Luttrell Psalter in the British Library.

1979, Paul Hulton, Lawrence Smith, “Naturalism in Sung China”, in Flowers in Art from East and West‎, Jarrold and Sons, page 3

But keep on the lookout for the 1st-century-a.d. stele on the right wall, with symbols of the deceased’s civic scribely duties (a scroll and codex), and the fresco remnants around to the left.

2010, John Moretti, “Perugia, Assisi & Northern Umbria”, in Florence, Tuscany & Umbria (Frommer’s), 7th edition, Wiley Publishing, Inc., section 2 (Assisi: An Artistic Pilgrimage), page 393

Many neurodegenerative diseases, including Alzheimer's disease (AD), involve pathological protein deposits.

2015 — Larochelle, Stéphane (December 2015). "STOMPing at the bits". Nature Methods 12 (12): 1114. doi:10.1038/nmeth.3679. Retrieved 19 February 2016.