0 the period that starts at about twelve o'clock or after the meal in the middle of the day and ends at about six o'clock or when the sun goes down:
1 a friendly way of greeting someone when you meet them in the afternoon:
Afternoon, Bob!
2 the period that starts at about twelve o’clock or after the meal in the middle of the day and ends at about six o’clock or when the sun goes down:
It had been raining hard most of the afternoon.
I will have to cancel this afternoon's class - I'm sorry it's such short notice.