Source : Webster's Revised Unabridged Dictionary (1913)

Acquaint \Ac*quaint"\, v. t. [imp. & p. p. {Acquainted}; p. pr.
   & vb. n. {Acquainting}.] [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.

   Syn: To inform; apprise; communicate; advise.

Acquainted \Ac*quaint"ed\, a.
   Personally known; familiar. See {To be acquainted with},
   under {Acquaint}, v. t.

Source : WordNet®

acquainted
     adj : having fair knowledge of; "they were acquainted"; "fully
           acquainted with the facts" [syn: {acquainted(p)}, {acquainted
           with(p)}, {familiar with(p)}]