a.m.
adverb
- period of the day after midnight and before noon
Wiktionary
adj
Etymology: Abbreviation of ante meridiem (“before noon”).
- Initialism of ad modum.
adv
Etymology: Abbreviation of ante meridiem (“before noon”).
- In the 12-hour period from midnight to noon (the first half of the day) when using the 12-hour clock.
“Greenfield … Monday thru Friday, 9 to 12 a.m.”
“One of the most common night shifts is the 12 a.m.-to-8 a.m. shift.”
noun
- Initialism of anno mundi.
- Initialism of Master of Arts.