enter vs obtrude upon

enter and obtrude upon both are verbs.

Word	Noun	Adjective	Verb	Adverb
enter	No	No	Yes	No
obtrude upon	No	No	Yes	No

As verbs, obtrude upon is a hyponym of enter; that is, obtrude upon is a word with a more specific, narrower meaning than enter:

enter (verb)	obtrude upon (verb)
set out on (an enterprise or subject of study)	to intrude upon, infringe, encroach on, violate
make a record of; set down in permanent form
become a participant; be involved in
put or introduce into something
come on stage
to come or go into
take on duties or office
register formally as a participant or member
be or play a part of or in