Lewis & Short

sĭnŭo, āvi, ātum, 1, v. a. [sinuo].

  1. I. Lit., to bend, wind, curve; to bow, to swell out in curves (perh. not ante-Aug.; most freq. in the poets; syn.: curvo, flecto): (anguis) sinuat immensa volumine terga, Verg. A. 2, 208; cf.: flexos corpus in orbes (anguis), Ov. M. 9, 64: (equus) sinuet alterna volumina crurum, Verg. G. 3, 192: imposito patulos calamo sinuaverat arcus, i. e. had bent, stretched, Ov. M. 8, 30; so, arcum, id. ib. 8, 381: nervum, Sen. Herc. Fur. 1198: Euphraten immensum attolli et in modum diadematis sinuare orbes, Tac. A. 6, 37: (anguis) immensos saltu sinuatur in arcus, Ov. M. 3, 42; cf.: gurges curvos sinuatus in arcus, id. ib. 14, 51: cornua Lunae sinuantur, id. ib. 3, 682; 14, 501; Cels. 8, 1 med.: muri per artem obliqui aut introrsus sinuati, bent inwards, i. e. with retreating angles, Tac. H. 5, 11; cf.: exercitus in cornua, sinuatā mediā parte, curvatur, Sen. Vit. Beat. 4: (Chaucorum gens) donec in Chattos usque sinuetur, extends in a curve, Tac. G. 35: Ionia se ambagibus sinuat, Mel. 1, 17: oceanum, Claud. Rapt. Pros. 1, 271.
  2. * II. Transf., to hollow out, excavate: adhuc sana rodendo, Cels. 7, 2, § 21.