Greeting - combination of 'Morning (abbreviated from Good Morning) and 'Afternoon (abbr. Good Afternoon) used as a salutation when addressing someone later in the morning or early afternoon - typically roughly from somewhere between 11 am and 3 pm. Or when greeting people from varying time zones when the time range is similarly appropriate.
Might also be used to refer to that same time period being late Morning until early Afternoon.
MAfternoon! I know you were up late / likely slept in and I'm not sure when exactly you'll be reading this, but please give me a call when you're up and about.
Getting drunk, loud, and obnoxious during the afternoon daylight hours and talking lots of trash with violence usually happening as well, often domestic. Common in urban white environments like east Dayton, Ohio where ethnic Appalachian white trash abound.
Holy fuck Jerry put on an afternoon hillbilly today and beat his bitch right before CSIcame on.