1. personal knowledge or information about someone or something
2. a relationship less intimate than friendship
3. a person with whom you are acquainted
I have trouble remembering the names of all my acquaintances|we are friends of the family
4. A state of being acquainted, or of having intimate, or more than slight or superficial, knowledge; personal knowledge gained by intercourse short of that of friendship or intimacy; as, I know the man; but have no acquaintance with him.