Lewis & Short

gĕnu, ūs, n. (also nom. sing. gĕnum, n., Front. Ep. ad M. Caes. 5, 44; and gĕ-nus, m., Lucil. ap. Non. 207, 28; gen. sing. genuis; dat. genui, genu, Mart. Cap. 3, § 293.
In neutr., nom. and acc. sing. genus, Cic. Arat. 45; 46; 399; 403; plur. gēnvă, as a dissyllable, Carey’s Lat. Prosody, § 47; Verg. A. 5, 432; 12, 905; gen. plur. genuorum, Vitr. 9, 6 dub.; dat. plur. genubus, Sen. Thyest. 406; Hippol. 667; Mart. Cap. 3, § 293; but usu. genibus, Curt. 10, 5, 24; Tac. A. 12, 18; Liv. 44, 31 fin.; Ov. M. 13, 585) [kindr. with Sanscr. jānu; Gr. γόνυ; Goth. kniu; Germ. Knie; Engl. knee], the knee.

  1. I. Lit.: meus est ballista pugnus, cubitus catapulta est mihi, Umerus aries: tum genu ut quemque icero, ad terram dabo, Plaut. Capt. 4, 2, 17: hujus genus, Cic. ap. Serv. ad Verg. A. 3, 22: fine genus vestem ritu succincta Dianae, Ov. M. 10, 536: per aquam ferme genus tenus altam, Liv. 44, 40, 8 Drak. N. cr.: in ipsa genus utriusque commissura, knee-joint, Plin. 11, 45, 103, § 250: sedatis tibi doloribus genus, Fronto Ep. p. 134 Rom.: dolorem genus suscitare, id. ib. p. 138: ne quem in cursu capite aut cubito offendam aut genu, Plaut. Curc. 2, 3, 3: genu mehercule M. Antonium vidi, cum contente pro se ipse lege Varia diceret, terram tangere, Cic. Tusc. 2, 24, 57: genua inediā succidunt, Plaut. Curc. 2, 3, 30: dumque virent genua, Hor. Epod. 13, 4: genuum junctura, knee-joint, Ov. M. 2, 823: genuumque tumebat orbis, knee-pan, id. ib. 8, 809: ad genua accidere, Enn. ap. Non. 517, 16 (Com. Rel. v. 9 Vahl.): procidere, Sen. Contr. 7, 17, 12: ad genua se alicui submittere, Suet. Tib. 20; cf.: genua amplexus genibusque volutans Haerebat, Verg. A. 3, 607: atqui pol hodie non feres, ni genua confricantur, i. e. be clasped in earnest entreaty, Plaut. As. 3, 3, 80; so, fricare, ib. 88: nunc tibi amplectimur genua egentes opum, id. Rud. 1, 5, 16; cf.: exurgite a genibus, id. ib. v. 22: advolvi, Sall. Fragm. ap. Serv. Verg. A. 1, 311; Tac. A. 1, 13 fin.; 6, 49; 15, 71; for which: genibus se advolvere or advolvi, Liv. 8, 37 fin.; 28, 34, 4; Vell. 2, 80 fin.: nixi genibus ab senatu petierunt, ne, etc., Liv. 43, 2, 2: muta metu terram genibus summissa petebat, Lucr. 1, 92: corde et genibus tremit, Hor. C. 1, 23, 8: jus imperiumque Phraates Caesaris accepit genibus minor, i. e. kneeling, beseeching, id. Ep. 1, 12, 28; Vulg. Phil. 2, 10 saep.: genu ponere, to bow the knee, Curt. 4, 6, 28; so, alicui, id. 8, 7, 13: genu flectere, Hier. in. Eph. 3, 14: inflexo genu adorare aliquem, Sen. Herc. Fur. 410: nixi genibus, on bended knees, Liv. 43, 2, 2: per tua genua te opsecro, Plaut. Curc. 5, 2, 31: genua incerare deorum, i. e. to attach to the statues of the gods wax tablets with prayers written on them, Juv. 10, 55.
  2. II. Transf., of plants, a knot, joint, usually called geniculum: a genibus (ferulae) exeuntia folia, Plin. 13, 22, 42, § 123.