Real Dictionary

party
countable noun: A party is a political organization whose members have similar aims and beliefs. Usually the organization tries to get its members elected to the government of a country.

party in American English
a group of people working together to establish or promote particular theories or principles of government which they hold in common; esp., an organized political group which seeks to elect its candidates to office and thus to direct government policies
adjective: of or pertaining to a party or faction; partisan
intransitive verb: to go to or give parties, esp. a series of parties
noun: a social gathering, as of invited guests at a private home, for conversation, refreshments, entertainment, etc

party in British English
noun: a social gathering for pleasure, often held as a celebration

party in Hospitality
noun: A party of people is a group of people who are doing something together, for example, eating at a restaurant or staying in a hotel.