An acquaintance is someone you know a little about, but they’re not your best friend or anything. Acquaintance is also having knowledge about something specific, like horror films or the farming techniques of Chinese peasants.
The root of acquaintance is the Old French word acointier, a verb meaning “make known.” Being the acquaintance of a person or topic means that you know something about it. An acquaintance is less intimate than a friend, like a person in your class whose name you know, but that’s it. When you “make the acquaintance of” someone, you meet them for the first time. If you know nothing about eggplants, you’d say, “I have little acquaintance with eggplants.”