divide vs keep apart

divide is a noun but keep apart is not a noun.

Word	Noun	Adjective	Verb	Adverb
divide	Yes	No	Yes	No
keep apart	No	No	Yes	No

As verbs, keep apart is a hyponym of divide; that is, keep apart is a word with a more specific, narrower meaning than divide:

divide (noun)	keep apart (noun)
a ridge of land that separates two adjacent river systems
a serious disagreement between two groups of people (typically producing tension or hostility)

divide (verb)	keep apart (verb)
perform a division	set apart from others
move or break apart
force, take, or pull apart
make a division or separation
separate into parts or portions
act as a barrier between; stand between