1. Before Christ. Often written in small caps.

   The Han Dynasty ruled China from 206 BC to AD 220.

2. British Columbia, a Canadian province.
3. Baja California, a Mexican state.
4. birth control

Usage notes

• The Chicago Manual of Style as well as most house styles require placing the AD before the number of the year and BC after, although in casual use either can be found following the year.

Antonyms

• (before Christ): a.d., AD, A.D., anno Domini, annō Domini, Anno Domini, CE, Common Era, in the year of our Lord

1. British Columbia, a province of Canada.
2. battlecruiser, a type of warship.