I.v. a., to unlearn, to forget, sc. what one has learned (rare, but class.).
(α).
With acc.: “qui, quod didicit, id dediscit,” Plaut. Am. 2, 2, 56; cf.: “multa oportet discat atque dediscat,” Cic. Quint. 17 fin.; so, “haec verba,” id. Brut. 46, 171; cf. id. de Or. 3, 24, 93: nomen disciplinamque populi Romani, * Caes. B. C. 3, 110: “sermonem,” Quint. 1, 1, 5: “cordaque languentem dedidicere metum,” Claud. Praef. Rapt. Pros. 1, 10: dedidicit jam pace ducem, has unlearned the general, i. e. lost his military character, Luc. 1, 131: “dedisce captam,” Sen. Troad. 887.—Prov.: “dediscit animus sero quod didicit diu,” id. ib. 631.—
(β).
With inf.: “(eloquentia) loqui dedisceret,” Cic. Brut. 13, 51; “so loqui,” Ov. Tr. 3, 14, 46: “amare,” id. R. Am. 297 al.