What is the full form of am & pm?

Question

What is the full form of am & pm?

Answer 1

ante meridian

post meridian

Note on Clavius's answer below: a dictionary would show that either form is acceptable.

Note 2: Dictionaries are base on usage and not the other way around.  If usage goes from Latin to Anglicized versions, that is just the way language evolves.

Answer 2

Ante Meridian

Prime Meridian

Answer 3

FYI the terms mean before or after the sun crosses the meridian, the imaginary line in the sky lying due south, i.e., before or after noon, literally.

Answer 4

Clavius's answer is the correct one...and the terms are Latin in origin!  

Rock on, Clavius!

Answer 5

For the simpleton ..  AM = after midnight  Pm = past Midday  

Answer 6

Ante and post meridiem (not meridian).

EDIT 1:

No.  "Meridian" is a common misspelling, but it is not correct Latin; it is an English word.  "Ante meridianum" would be correct; "ante meridiem" would be correct.  But "ante meridian" is a mish-mash of Latin and English.

EDIT 2:

To clarify:  "meridianus" is the adjective meaning "pertaining to midday."  "Meridies" is the noun meaning "noon" or "midday."  In Latin as in English, prepositions most simply take nouns as their objects; hence "meridiem" is preferred as the object, and strictly required if good Latin is practiced.  "Meridianum" can be read "that which pertains to midday," hence "ante meridianum" can mean "before that which pertains to midday," but that reading is stilted and contrived although grammatically acceptable.

There is no Latin word "meridian."  Dictionaries which purport that "meridian" is an acceptable expansion of the Latin abbrevations are wrong.

Answer 7

There is a place in Great Britain where the official time of every day is  determined to start throughout the whole World. This is at the place on the longitudinal line on the Earth's globe which passes through Greenwich, England, the *Official, World-Wide Starting Point for World-Wide Clock-Adjusting (dependent on Time Zones all throughout the Globe)!

All of the aforesaid being presented, in simple terms:

a.m. refers to *morning* (before lunch) times.

'Noon*  refers to the mid-day time, @ 12:00 o'clock lunch, etc.

p.m. refers to the evening hours when, usually, a 'Dinner' meal is

        served.

Answer 8

ante meridiem, meaning “before noon.''

post meridiem, meaning the period between noon and midnight.