Smith's Bible Dictionary 
Pris'ca. (Ancient). 2 Timothy 4:19. Pris'ca or Priscil'la, (a diminutive from Prisca). The wife of Aquila. See Aquila . To what has been said elsewhere under the head of Aquila , the following may be added:
We find that the name of the wife is placed before that of the husband in Romans 16:3; 2 Timothy 4:19, and , (according to some of the best manuscripts), in Acts 18:26. Hence, we should be disposed to conclude that Priscilla was the more energetic character of the two. In fact, we may say that Priscilla is the example of what the married woman may do for the general service of the Church, in conjunction with home duties, as Phoebe is the type of the unmarried servant of the Church, or deaconess.
Holman Bible Dictionary 
Kitto's Popular Cyclopedia of Biblial Literature