Acquaintance - (Webster's 1828 Dictionary)
1. Familiar knowledge; a state of being acquainted, or of having intimate or more than slight or superficial knowledge; as, I know the man, but have no acquaintance with him. Sometimes it denotes a more slight knowledge.
2. A person or persons well known; usually persons we have been accustomed to see and converse with; sometimes, persons more slightly known.
Lover and friend has thou put far from me and mine acquaintance into darkness. Psa 88.
My acquaintance are estranged from me. Job 19.
Acquaintances, in the plural is used, as applied to individual persons known; but more generally, acquaintance is used for one or more.
Acquaintant, in a like sense, is not used.