Lewis & Short

dē-disco, dĭdĭci, 3, v. a., to unlearn, to forget, sc. what one has learned (rare, but class.).

        1. (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.
        2. (β) With inf.: (eloquentia) loqui dedisceret, Cic. Brut. 13, 51; so loqui, Ov. Tr. 3, 14, 46: amare, id. R. Am. 297 al.