overrun vs get the better of

overrun is a noun but get the better of is not a noun.

Word	Noun	Adjective	Verb	Adverb
overrun	Yes	No	Yes	No
get the better of	No	No	Yes	No

As verbs, get the better of is a hypernym of overrun; that is, get the better of is a word with a broader meaning than overrun:

Other hypernyms of overrun include defeat, overcome.

overrun (noun)	get the better of (noun)
too much production or more than expected

overrun (verb)	get the better of (verb)
run beyond or past	win a victory over
seize the position of and defeat
flow or run over (a limit or brim)
invade in great numbers
occupy in large numbers or live on a host