party vs lawn party

party and lawn party both are nouns.

Word	Noun	Adjective	Verb	Adverb
party	Yes	No	Yes	No
lawn party	Yes	No	No	No

As nouns, lawn party is a hyponym of party; that is, lawn party is a word with a more specific, narrower meaning than party:

party (noun)	lawn party (noun)
an occasion on which people can assemble for social interaction and entertainment	a party of people assembled for social interaction out of doors
a gathering of people for pleasure
an organization to gain political power
a band of people associated temporarily in some activity
a person involved in legal proceedings

party (verb)	lawn party (verb)
have or participate in a party