a 'garden party' [=a party that takes place in a garden or in a large yard with gardens]
They went to the hockey game at Madison Square 'Garden'.
He doesn't have the flu—just a 'garden-variety' cold.
(..) What are we gonna to do with nothin' to feed those sick folks and that child? I don't know, Mammy. I don't know. We ain't got nothin' but radishes in the garden. Miss Scarlett, Miss Suellen and Miss Carreen... ...they's fussin' to be sponged off. Where are the other servants, Mammy? (..)1939 Gone with the Wind
(..) Now you've got to listen to me. You must stay here! Without a chaperon, Dr. Meade? It simply isn't done! Good heavens, woman, this is war, not a garden party! You've got to stay. Melanie needs you. Oh, bother Melanie. She's ill already. She shouldn't even be having a baby. (..)1939 Gone with the Wind