Lewis & Short

ascriptor (adscr-), ōris, m. [ascribo, I.], he who willingly subscribes (his name); hence, trop., he who subscribes to, agrees to, approves any thing (perh. only in the foll. exs.): ascriptores legis agrariae, Cic. Agr. 9: venalis ascriptor et subscriptor tuus, id. Dom. 19; id. Red. in Sen. 4, 9; 10, 26.