ACCA.  m. Anglo-Saxon name derived from the vocabulary word aec, meaning "oak."

... The reason why a man was called after the ash tree is explained on mythological grounds,... Nor is it difficult to conceive why a man should be called after the oak, the emblem of stability and strength.  This seems to be the origin of several ancient Saxon names, as Æcca, or Æcci, bishop of the East Angles, Acca, bishop of Hexham, Ecca and Occa in the royal line of Northumberland.  All these seem to be from Ang.-Sax. ác, aec, Old Norse eyk, Dutch aik, eek, an oak. (English Surnames, and Their Place in the Teutonic Family, Ferguson, 1858)

ACCA.  f. Latin name rendered "mother" by most authors, but it may actually mean "cow."  See note below.

The wife of Faustulus was named Acca Laurentia.  In Acca, when we aspirate its first letter, we see Hacca, which cannot differ from vacca any more than hesper can from vesper; and as vacca means a cow, this may account for any one so called being the wife of a pastor or cowkeeper. (Origin of Language and Myths, Kavanagh, 1871)

ACCA.  Sister and companion of Camilla, queen of the Volsci.  Besides this Acca there was ACCA LAURENTIA, wife to Faustulus the shepherd of Numitor, and nurse to Romulus and Remus.  She is represented as not less conspicuous for the beauty of her person than her salaciousness of manners, which procured her the name of Lupa or She-wolf.  Divine honours were decreed her by the Romans, and a festival instituted under the name of Laurentalia, which, according to Varro, was celebrated in April; or, as Ovid says, in December.  This difference as to time, may, however, be accommodated by Plutarch.  He mentions a festival, in honour of a courtezan of the same name, who having married a rich old man, bequeathed her estate to the people by will.  These feasts were called Accalia. (Bell's New Pantheon, 1790)