Lewis & Short

formīdŭlōsus (formīdŏlōsus, v. Corss. Ausspr. 2, 145), a, um, adj. [2. formido], full of fear, fearful.

  1. I. Act., producing fear, dreadful, terrible, terrific (class.): nimis formidulosum facinus praedicas, Plaut. Am. 5, 1, 65: loca tetra, inculta, foeda, formidulosa, Sall. C. 55, 13: hunc locum consessumque vestrum, quem illi horribilem A. Cluentio ac formidulosum fore putaverunt, Cic. Clu. 3, 7: ferae, Hor. Epod. 5, 55: seu me Scorpius aspicit Formidolosus, id. C. 2, 17, 18: herbae formidolosae dictu, non esu modo, Plaut. Ps. 3, 2, 35: facinus, id. Am. 5, 1, 65: dubia et formidulosa tempora, Cic. Verr. 2, 5, 1, § 1: formidulosissimum bellum, id. Pis. 24, 58; id. de Imp. Pomp. 21, 62: in vulgus, Tac. A. 1, 76.
  2. II. Pass., experiencing fear, afraid, timid, timorous (rare; not in Cic.): mancipia esse oportet neque formidolosa neque animosa, Varr. R. R. 1, 17, 3: num formidolosus, obsecro, es? Ter. Eun. 4, 6, 18 sq.: (boyes) ad ingredienda flumina aut pontes formidolosi, Col. 6, 2, 14: equus, Sen. Clem. 17.
    Comp.: exercitum formidolosiorem hostium credere, Tac. A. 1, 62.
    Hence, adv.: formīdŭlōse.
      1. * 1. Fearfully, dreadfully, terribly, Cic. Sest. 19, 42.
      2. * 2. Fearfully, timidly, timorously: formidolosius, Cato ap. Charis. p. 196 P.