daytime vs midafternoon

daytime and midafternoon both are nouns.

Word	Noun	Adjective	Verb	Adverb
daytime	Yes	No	No	No
midafternoon	Yes	No	No	No

As nouns, midafternoon is a hyponym of daytime; that is, midafternoon is a word with a more specific, narrower meaning than daytime:

Other hyponyms of daytime include afternoon, eve, even, evening, eventide.

daytime (noun)	midafternoon (noun)
the time after sunrise and before sunset while it is light outside	the middle part of the afternoon