What is Common-law Action?

Legal Definition
A civil suit, as distinguished from a criminal prosecution or a proceeding to enforce a penalty or a police regulation ; not necessarily an action which would lie at common law. Kirby v. Railroad Co. (Cl Ct) 106 Fed. 551; U. S. v. Bloc 33 Or. 584, 56 Pac. 275, 44 L. R. A. 266, 72 Am. St. Rep. 758.
-- Black's Law Dictionary