Definition of party:
an organization to gain political power; "in 1992 Perot tried to organize a third party at the national level"
a group of people gathered together for pleasure; "she joined the party after dinner"
a band of people associated temporarily in some activity; "they organized a party to search for food"; "the company of cooks walked into the kitchen"
an occasion on which people can assemble for social interaction and entertainment; "he planned a party to celebrate Bastille Day"
a person involved in legal proceedings; "the party of the first part"
have or participate in a party; "The students were partying all night before the exam"