1250-1300;Middle Englishaqueinten, acointen < Anglo-Frenchacointer,Old Frenchacoint(i)er, verbal derivative of acointe familiar, known < Latinaccognitus, past participle of accognōscere to recognize, equivalent to ac-ac- + co-co- + gni-know + -tus past participle suffix
c.1300, from O.Fr. acointier from V.L. *accognitare "to make known," from L. accognitus, pp. of accognoscere "know well," from ad- "to" + cognitus, pp. of cogniscere "come to know," from com- "with" + gnoscere "know" (see notice). Originally reflective, "to make oneself known;" sense of "to gain for oneself personal knowledge of" is from early 14c.