term that denotes the years before the supposed date of birth of Jesus Christ in the Christian calendar
The term ante Christum natum (Latin for 'before Christ [was] born'), usually abbreviated to a. Chr. n., a.Ch.n., a.C.n., A.C.N., or ACN, denotes the years before the birth of Jesus. It is a Latin equivalent to the English "BC" ("before Christ"). The phrase ante Christum natum is also seen shortened to ante Christum ("before Christ"), similarly abbreviated to a. Chr., A. C. or AC. A related phrase, p. Chr. n., p. Ch. n., P.C.M, PCN, or post Christum natum complements a. Ch. n. and is equivalent to anno Domini (AD).
In English, these phrases are rare and AC, ACN, and ante Christum natum are not in the Chicago Manual of Style (14th edition), the American Heritage Dictionary (3rd edition), or P. Kenneth Seidelmann's Explanatory Supplement to the Astronomical Almanac (1992, University Science Books). In other European languages, such as Italian ("a.c." or "a.C." for avanti Cristo), a vernacular version is the standard term.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).