Lewis & Short

quercus, ūs (gen. querci, Pall. 4, 7, 8; gen. plur. quercorum, Cic. Fragm. ap. Prisc. p. 717 P.; dat. and abl. plur. do not occur), f. [perh. from root kar (kal-k), to be hard; cf.: cornu calx, calculus].

  1. I. An oak, oaktree, esp. the Italian or esculent oak, sacred to Jupiter (cf. robur): quercus dicitur, quod id genus arboris grave sit ac durum, tum etiam in ingentem evadat amplitudinem: querqueram enim gravem et magnam putant dici, Paul. ex Fest. p. 259 Müll.: percellunt magnas quercus, Enn. ap. Macr. S. 6, 2 (Ann. v. 194 Vahl.): magna Jovis quercus, Verg. G. 3, 332: glandiferae, Lucr. 5, 939; Cic. Leg. 1, 1, 2: aëriae, Verg. A. 3, 680: quercus et ilex Multā fruge pecus juvat, Hor. Ep. 1, 16, 9: auritae, id. C. 1, 12, 12: aridae, id. ib. 4, 13, 10: durior annosā quercu, Ov. M. 13, 799: quercorum rami, Cic. Fragm. ap. Prisc. p. 717 P.
  2. II. Poet., transf.
    1. A.
      Note:f things made of oak-wood. Of a ship, of the ship Argo, Val. Fl. 5, 65.
      Of a javelin, Val. Fl. 6, 243.
      Of a drinkingvessel, Sil. 7, 190.
      Capitolina, a garland of oak-leaves, Juv. 6, 386; usually bestowed upon one who had saved the life of a citizen in battle, Ov. F. 4, 953; id. M. 1, 563; Luc. 1, 357: civilis, Verg. A. 6, 772.
    2. B. For acorns (very rare): veteris fastidia quercūs, Juv. 14, 184.