From Longman Dictionary of Contemporary Englishhouse partyˈhouse ˌparty noun [countable] DLPARTYa group of people who stay as guests in someone’s house and have a party there
Examples from the Corpus
house party• S., discotheques became popular as places you danced to recorded music, just like at a house party.• I have heard of various instances of a butler being displayed as a kind of performing monkey at a house party.• They still spent Christmas quietly and had a big house party for the New Year.• Organised on house party lines, they have proved most popular.• But their efforts at conversation became increasingly difficult as the surrounding house party grew more and more riotous. 