A person whom one knows casually
Personal knowledge derived from participation or observation
The state of being acquainted
A person with whom one is acquainted
Knowledge gained through personal experience or study
He's not a casual acquaintance whom you barely know.
Happy to make your acquaintance, Miss Sidwell.
He had an acquaintance with the literature.
Be sure to come: you may meet some old acquaintance.
The job interview especially is a moment of mutual acquaintance.