What does acquaint mean?
The definition of acquaint
Ac*quaint”, a.
Etym: [OF. acoint. See Acquaint, v. t.]

Acquainted. [Obs.]

Ac*quaint”, v. t.
[imp. & p. p. Acquainted; p. pr. & vb. n.Acquainting.]
Etym: [OE. aqueinten, acointen, OF. acointier, LL. adcognitare, fr. L. ad + cognitus, p. p. of cognoscere to know; con- + noscere to know. See Quaint, Know.]

1 To furnish or give experimental knowledge of; to make (one) to know; to make familiar; — followed by with. Before a man can speak on any subject, it is necessary to be acquainted with it. Locke. A man of sorrows and acquainted with grief. Isa. liii. 3.
2 To communicate notice to; to inform; to make cognizant; — followed by with (formerly, also, by of), or by that, introducing the intelligence; as, to acquaint a friend with the particulars of an act. Acquaint her here of my son Paris’ love. Shak. I must acquaint you that I have received New dated letters from Northumberland. Shak.
3 To familiarize; to accustom. [Obs.] Evelyn. To be acquainted with, to be possessed of personal knowledge of; to be cognizant of; to be more or less familiar with; to be on terms of social intercourse with.

Synonyms
— To inform; apprise; communicate; advise.