noun which may take the genitive case particle 'no'
Polite, often used attributively with の to describe something or someone familiar and well-known. Can refer to a regular customer or favorite thing.
See also: 馴染み
This is a familiar scene.
彼はこの店のおなじみの客です。
He is a regular customer at this shop.
noun
old acquaintance; old friend; regular
Polite noun referring to a person one knows well, an old friend, or a regular (e.g., at a shop). Often used with の to modify another noun.
彼は高校時代からのおなじみです。
He is an old friend from high school.
あの人はこの店のおなじみだ。
That person is a regular at this shop.