introduce vs stop up

introduce and stop up both are verbs.

Word	Noun	Adjective	Verb	Adverb
introduce	No	No	Yes	No
stop up	No	No	Yes	No

introduce (verb)	stop up (verb)
be a precursor of	fill or close tightly with or as if with a plug
place, fit, or thrust (something) into another thing
put before (a body)
cause to come to know personally
furnish with a preface or introduction
bring before the public for the first time, as of an actor, song, etc.
put or introduce into something
bring something new to an environment
bring in or establish in a new place or environment
bring in a new person or object into a familiar environment