Lewis & Short

subscriptor, ōris, m. [subscribo].

  1. I. (Acc. to subscribo, I. B. 1.) A signer or joint-signer of an accusation, Cic. Div. in Caecil. 15, 47; 16, 51: venalis scriptor et subscriptor tuus, id. Dom. 19, 49: accusatore Lentulo subscriptoribusque ejus, id. Q. Fr. 3, 4, 1: sine ullo subscriptore descendit, Cael. ap. Cic. Fam. 8, 8, 1.
  2. II. (Acc. to subscribo, I. B. 3. b.) One who subscribes or assents to any thing, a favorer, approver (post-class.): sententiae legisque fundus subscriptorque, Gell. 19, 8, 12: subscriptores approbatoresque verbi, id. 5, 21, 6.