a.m.; before noon
Used as a noun or suffix to indicate morning hours. Often follows a time expression, e.g. 午前10時ＡＭ.
The meeting starts at 10 a.m.
The meeting starts at 9:00 a.m.
AM broadcasting; amplitude modulation
Technical term for AM radio broadcasting. Often used in compounds like ＡＭ放送 or ＡＭラジオ.
AM broadcasts come in clearly in this area.
I like listening to AM broadcasting in the car.
Fullwidth lowercase variant; less common but acceptable.
Borrowed from English 'AM', an abbreviation of 'ante meridiem' for the time sense and 'amplitude modulation' for the broadcasting sense.