break up vs inject

break up and inject both are verbs.

Word	Noun	Adjective	Verb	Adverb
break up	No	No	Yes	No
inject	No	No	Yes	No

As verbs, inject is a hyponym of break up; that is, inject is a word with a more specific, narrower meaning than break up:

break up (verb)	inject (verb)
laugh unrestrainedly	give an injection to
break or cause to break into pieces	to introduce (a new aspect or element)
come to an end	to insert between other elements
separate (substances) into constituent elements or parts	feed intravenously
cause to go into a solution	take by injection
cause to separate	force or drive (a fluid or gas) into by piercing
close at the end of a session
bring the association of to an end or cause to break up
make a break in
set or keep apart
break violently or noisily; smash
attack with or as if with a pickaxe of ice or rocky ground, for example
release ice
destroy the completeness of a set of related items
take apart into its constituent pieces
suffer a nervous breakdown
disband
to cause to separate and go in different directions
discontinue an association or relation; go different ways