Lewis & Short

ex-păvesco, pāvi, 3, v. inch. n. and a., to be or become greatly terrified, to be very much afraid; to be greatly frightened at or afraid of, to fear greatly (perh. not anteAug.).

        1. (α) Absol.: expavescentibus repente, Plin. 23, 1, 24, § 49.
          With ad: ad tumultum aliquem. Plin. 10, 75, 97, § 209; cf.: cum ad id expavisset, Liv. 6, 34, 6.
          With ab: anseres a primo conspectu ejus expavescunt, Plin. 21, 11, 36, § 62; Vulg. Gen. 27, 33 al.
        2. (β) With acc.: tonitrua praeter modum, Suet. Aug. 90; id. Tib. 69: muliebriter ensem, Hor. C. 1, 37, 23: speciem adulantis, Tac. H. 2, 76: insidias, Suet. Claud. 36: mortem, id. Ner. 2: frigusque famemque, Juv. 6, 361: acres moles (Rhodanus), Sil. 3, 464: id, ut crimen ingens, expavescendum est, Quint. 9, 3, 35.