Lewis & Short

2. passīvus, a, um, adj. [patior],

  1. I. capable of feeling or suffering, passible, passive (post-class.): anima passiva et interibilis, Arn. 2, 65; App. de Deo Socr. p. 49.
  2. II. In partic., in gram., passive: verbum passivum . . . quod habet naturam patiendi, Quint. 1, 6, 10: verba, Charis. 2; Diom. 1; Prisc. 8 et saep.
    Adv.: pas-sīvē, passively, Lucil. ap. Prisc. p. 791 P.