Acting together or in concert or co-operation ; holding in common or interdependently, not separately. Reclamation Dist. v. Parvin, 67 Cal. 501, 8 Pac. 43; Gold & Stock Tel. Co. v. Commercial Tel. Co. (C. C.) 23 Fed. 342; Case v. Owen, 130 Ind. 22, 38 N. E. 395, 47 Am. St. Rep. 253. Persons are “jointly bound” in a bond or note when both or all must be sued in one action for its enforcement, not either one at the election of the creditor.