Lewis & Short

ĭnŏpīnātē and ĭnŏpīnātō, advv., v. inopinatus fin.

ĭn-ŏpīnātus, a, um, not expected, unexpected (class.).

  1. I. Adj.: cum hoc illi improvisum atque inopinatum accidisset, Cic. Verr. 2, 2, 28, § 69: nova tibi haec sunt et inopinata? id. ib. 2, 2, 8, § 24: neque novum neque inopinatum mihi sit, Liv. 6, 40, 3: nec hoc tam re est, quam dictu inopinatum atque mirabile, Cic. Par. 5, 1, § 35: malum, Caes. B. C. 2, 12: finis vitae, Suet. Caes. 87: fraus, Sil. 7, 133: id quoque scriptum est, quod volgo inopinatum est, contrary to the common belief, Gell. 11, 18, 13.
    Sup.: inopinatissim us sensus, Aug. Trin. 7, 1.
  2. II. Subst.: ĭnŏpīnātum, i, n., something unexpected: nihil inopinati accidit, Cic. Tusc. 3, 31, 76.
    Hence, ex inopinato, adverbially, unexpectedly: aliae ut ex inopinato observant, id. N. D. 2, 48, 123: repente ex inopinato prope cuncta turbata sunt, Suet. Galb. 10.
    Adv. in two forms.
      1. 1. ĭnŏpīnātē, unexpectedly: aliquem inopinate occupare, Sen. ad Helv. 5.
      2. 2. ĭnŏpīnātō, unexpectedly: in castra irrumpere, Liv. 26, 6, 9.