a.m.

1. before noon.
2. the period from midnight to noon, especially the period of daylight prior to noon: Shall we meet Saturday a.m.?
3. a morning newspaper, sometimes issued shortly before midnight.

1. a.m.
2. Master of Arts.

1. Agricultural and Mechanical (college): Texas A and M.

abbreviation for (indicating the time period from midnight to midday)

1. ante meridiemCompare p.m.

in hours, 1762, abbreviation of Latin ante meridiem “before noon.”

also AM, type of radio wave broadcast; see amplitude.