At the suit of. Com-nionly abbreviated to ads. Used iu entering and indexing the names of cases, where it is desired that the name of the defendant should come first. Thus. “B. ads. A.” in-dlcates that B. is defendant in an action brought by A., and the title so written would be an inversion of the more usual form “A. v. B.”
Source: Black's Law Dictionary 2nd Ed (1910)
