ac·quain·tance 
(ə-kwāntəns)
(ə-kwāntəns)n.
Idiom: 1.
a. Knowledge of a person acquired by a relationship less intimate than friendship.
b. A relationship based on such knowledge: struck up an acquaintance with our new neighbor.
2. A person whom one knows.
3. Knowledge or information about something or someone: has a passing acquaintance with Chinese history.
make (someone's) acquaintance
To meet someone for the first time: I made his acquaintance at a business conference.
ac·quaintance·ship′ n.