Definitions

1. noun

A year, especially as a unit of time in the past, especially in the phrase ‘anno Domini’ (AD) or ‘anno Mundi’ (AM), denoting the number of years since the traditional date of the Creation of the world or the birth of Jesus Christ.

“The historical event took place anno 1346.”

2. adverb

In or during a given year, especially in the sense of the year in which something is happening.

“The book was written anno the Great Fire of London.”

3. adverb

In or of the year in question.

“He was born anno 1945.”