Definition from Wiktionary, the free dictionary
midafternoon (plural midafternoons)
- The middle of the afternoon, normally between 2:00pm and 4:00pm.
- I'm not available until midafternoon, but feel free to call then.
- I'm going to enjoy a quiet midafternoon nap before it's time for tea.
middle of the afternoon
This is very often used attributively.