AM
Abbreviation with 11 meanings
| Stands for | Ante meridiem (before midday) |
|---|---|
| Meanings | 11 |
| Categories | Writing & Everyday, Technology & Computing, Transportation & Travel, Geography & Places, Science & Engineering, Business & Finance, Education & Academia, Military, Religion |
| Also written | a.m., Am |
AM has 11 meanings. The most common are Ante meridiem (before midday) (Latin) and Amplitude modulation (telecom); it can also stand for Aeroméxico, Armenia, Americium, Account manager and Artium Magister (Master of Arts), plus 4 more listed below.
Meanings of AM at a glance
| # | AM stands for | Context |
|---|---|---|
| 1 | Ante meridiem (before midday) | Writing & Everyday › Latin |
| 2 | Amplitude modulation | Technology & Computing › Telecom |
| 3 | Aeroméxico | Transportation & Travel › Airline Code |
| 4 | Armenia | Geography & Places › Country Code |
| 5 | Americium | Science & Engineering › Chemical Element |
| 6 | Account manager | Business & Finance › Job Title |
| 7 | Artium Magister (Master of Arts) | Education & Academia › Degree |
| 8 | Air Marshal | Military › British Military Rank |
| 9 | Aviation Structural Mechanic | Military › US Navy and Coast Guard Rating |
| 10 | Amos | Religion › Bible Book |
| 11 | Anno Mundi (in the year of the world) | Religion › Religious Term |
1. Ante meridiem (before midday) (a.m.)
Writing & Everyday · Latin Abbreviations · also used in measurement
Marks clock times from midnight up to noon in the 12-hour system used in the United States, Canada, Australia and much of the English-speaking world. Twelve-hour clocks pair it with p.m. so that 7 a.m. and 7 p.m. are never confused.
Example: The pharmacy opens at 8 a.m. on weekdays and at 10 a.m. on Sundays.
AP and Chicago use lowercase with periods (a.m.); British style often drops the periods (am), and some books set it in small capitals. Do not combine it with "in the morning" (redundant) or with "o'clock." Midnight and noon are ambiguous on a 12-hour clock: 12 a.m. conventionally means midnight, but many style guides recommend writing "midnight" or "noon" to avoid confusion.
2. Amplitude modulation
Technology & Computing · Telecom Abbreviations · also used in science
Method of transmitting audio by varying the strength (amplitude) of a radio carrier wave, used by AM broadcast radio on medium-wave frequencies, as well as by aviation radios and shortwave stations.
Example: At night, AM stations from hundreds of miles away come in clearly on the car radio.
The US AM broadcast band runs from about 530 to 1700 kHz. Medium-wave signals bounce off the ionosphere after dark, allowing very long-distance reception. Several carmakers dropped AM radios from electric vehicles, citing electrical interference, prompting proposed US legislation to keep them for emergency alerts. AM also means ante meridiem, before noon.
3. Aeroméxico
Transportation & Travel · Airline Code Abbreviations
Mexico's flag carrier, based in Mexico City and a founding member of SkyTeam. It has a joint venture with Delta Air Lines on US-Mexico routes.
Example: AM 403 from JFK to Mexico City boards at gate 25.
ICAO code AMX; callsign "Aeroméxico." Founded in 1934. Its eagle-warrior logo is drawn from Aztec imagery. Aeroméxico restructured in US bankruptcy court during the COVID-19 pandemic and emerged in 2022.
4. Armenia
Geography & Places · Country Code Abbreviations
Code for Armenia, the South Caucasus republic with Yerevan as its capital and alpha-3 ARM. The .am domain is popular with AM radio stations and with sites wanting a short English-looking address.
Example: The parcel to Yerevan was marked AM, and customs cleared it within a day.
Armenia was the first country to adopt Christianity as a state religion, traditionally dated to 301. The language code for Armenian is hy, from the native name Hayastan, while am is the code for Amharic.
5. Americium (Am)
Science & Engineering · Chemical Element Abbreviations
Americium (element 95) is the synthetic element found in many ordinary homes: a fraction of a microgram of americium-241 inside an ionization smoke detector ionizes the air in a sensing chamber, and smoke particles interrupt the resulting tiny current, setting off the alarm.
Example: The label on the smoke alarm reads: contains 0.9 microcurie of Am-241, a radioactive material.
Glenn Seaborg, Ralph James, Leon Morgan and Albert Ghiorso identified americium in 1944 at the wartime Metallurgical Laboratory in Chicago. It was named after the Americas by analogy with europium, the element directly above it in the periodic table. Seaborg first revealed the discovery on a children's radio quiz show in November 1945, days before the official announcement.
6. Account manager
Business & Finance · Job Title Abbreviations
Professional responsible for maintaining and growing relationships with existing customers, handling renewals, upsells, issues and day-to-day coordination after the initial sale. Account managers are common in software, advertising agencies, logistics and wholesale distribution.
Example: Your AM will schedule a quarterly review to go through usage and renewal options.
The role differs from an account executive, who wins new business, and overlaps with customer success manager. AM is far more widely known as the abbreviation for ante meridiem (morning) and for amplitude modulation radio.
7. Artium Magister (Master of Arts)
Education & Academia · Degree Abbreviations
Latin word-order form of the Master of Arts awarded by Harvard's Graduate School of Arts and Sciences, Brown and the University of Chicago, among others. It is identical in standing to an MA and is often awarded to doctoral students partway through a PhD.
Example: He received an AM in history from Harvard before completing his dissertation.
Written A.M. in older style. Schools that use AM usually also award the AB for undergraduates. Because "AM" also means morning, radio and other things, CVs often add the field and school, as in "AM, Economics, University of Chicago".
8. Air Marshal
Military · British Military Rank Abbreviations
Three-star RAF rank at NATO grade OF-8, equivalent to a lieutenant general or vice admiral. Air marshals hold senior command and staff posts, such as deputy commander of the RAF's air command or senior joint appointments.
Example: AM Hayes was appointed to lead the joint command at the Northwood headquarters.
Air marshals are customarily knighted or appointed to an order of chivalry on reaching the rank, though the practice has become less automatic. Commonwealth air forces such as the Royal Australian Air Force also use the rank, often for their service chief.
9. Aviation Structural Mechanic
Military · US Navy and Coast Guard Rating Abbreviations
Maintainers of aircraft airframes, flight-control surfaces, landing gear, hydraulic systems and fuselage repairs, including corrosion control. A related specialty, AME, covers safety and survival systems such as ejection seats, canopies and oxygen systems.
Example: AM2 Diaz inspected the landing gear struts after the hard landing.
AMEs carry special qualifications because ejection seats contain explosive cartridges. The Royal Air Force uses AM for Air Marshal, a three-star rank, and broadcast radio uses AM for amplitude modulation, so context matters when the letters appear outside naval aviation.
10. Amos (Am)
Religion · Bible Book Abbreviations
Prophetic book of nine chapters by a shepherd from Tekoa who denounced injustice and empty ritual in the northern kingdom of Israel around 760 BC. Its call "let judgment run down as waters, and righteousness as a mighty stream" (5:24) was quoted by Martin Luther King Jr.
Example: Am 5:24 is engraved on the Civil Rights Memorial in Montgomery.
Amos is not abbreviated by SBL or Chicago's traditional list, but Catholic Bibles and Chicago's short forms use Am. Context separates it from a.m. and other meanings of AM. Amos is often considered the first of the writing prophets.
11. Anno Mundi (in the year of the world)
Religion · Religious Term Abbreviations
Calendar era counting years from the supposed creation of the world, used in the Hebrew calendar, which places creation in 3761 BC. The Jewish year 5787 AM began at Rosh Hashanah in the fall of 2026.
Example: The ketubah was dated in the Hebrew year 5784 AM.
The Byzantine Empire used a different Anno Mundi era, dating creation to 5509 BC, which Russia used until Peter the Great adopted AD dating in 1700. To estimate a Hebrew year, add 3760 to the Gregorian year (3761 after Rosh Hashanah). Context separates AM from a.m. (morning) and AM radio.
Related abbreviations
More Latin abbreviations
- a.u.c. – Ab urbe condita (from the founding of the city)
- AD – Anno Domini (in the year of the Lord)
- ad inf. – Ad infinitum (to infinity)
- ad lib. – Ad libitum (at one's pleasure)
- aet. – Aetatis (aged, at the age of)
- c. – Circa (around, approximately)
- cet. par. – Ceteris paribus (other things being equal)
- cf. – Confer (compare)
See all 53 Latin abbreviations →