Lewis & Short

cō-nīvĕo (less correctly con-nī-vĕo; cf. Ritschl, Opusc. II. 448 sq.), nīvi (Cassius ap. Prisc. p. 866 P.; cf. Prob. II. p. 1482 ib.) or nixi (Turp. ap. Prisc. p. 866 P.; perh. also connipsi, connipseram, App. M. 11, p. 146 Hildebr. Min.), 2 (access. form of inf. conivĕre, Calvus ap. Prisc. l. l.), v. n. [niveo, kindr. with nico and nicto], to close or shut.

  1. * I. In gen.: cava ventris ac stomachi inanitate diutinā contrahuntur et conivent, Gell. 16, 3, 3.
    More freq.,
  2. II. Esp., to close or shut the eyes (in sleep, from the light, from fear, etc.), to blink; or of the eyes, to close, shut, to half close when heavy with sleep (class. in prose and poetry).
    1. A. Lit.: dum ego conixi somno, hic sibi prospexit vigilans virginem, Turp. l. l.; so Cic. Tusc. 1, 49, 117; Tac. A. 16, 5: coniventes illi oculi abavi tui, Cic. Har. Resp. 18, 38: conivent solemque pavent agnoscere visu, Sil. 7, 729; cf. Plin. 10, 3, 3, § 10: ad tonitrua et fulgura, Suet. Calig. 51: contra conminationem aliquam (gladiatores), Plin. 11, 37, 54, § 144.
      With acc. Gr.: nam non conivi oculos ego deinde sopore, Cassius, l. l.: (oculis) somno coniventibus, Cic. N. D. 2, 57, 143; Col. 10, 259.
      1. * 2. Poet., transf., of the sun and moon, to be darkened, obscured, eclipsed, Lucr. 5, 776.
    2. B. Trop.
      1. 1. In gen., to be dull, drowsy, or languid: certa sunt enim pleraque et nisi coniveamus, in oculos incurrunt, Quint. 10, 3, 16: multa nobis blandimenta natura ipsa genuit, quibus sopita virtus coniveret, Cic. Cael. 17, 41: animus atque mens viri prudentis in sollicitis numquam conivens, nusquam aciem suam flectens, etc., Gell. 13, 27, 4; cf. id. 2, 2, 9.
      2. 2. (Like our phrase to wink at.) To leave an error or crime unnoticed or uncensured, to overlook, connive at, wink at, etc.: haec ipsa concedo: quibusdam etiam in rebus coniveo, Cic. Phil. 1, 7, 18: pro di immortales! cur interdum in hominum sceleribus maxumis aut conivetis aut … poenas in diem reservetis? id. Cael. 24, 59: qui ob eam causam in tot tantisque sceleribus conivebant, id. Har. Resp. 24, 52; id. Agr. 2, 28, 77; Fragm. ap. Prob. II. p. 1482 P.: seditiosorum punitor acerrimus, conivebat in ceteris, Suet. Caes. 67; Pers. 6, 50.