Lewis & Short

rūgo, āvi, ātum, 1, v. n. and a. [1. ruga].

  1. I. Neutr., to crease, wrinkle; transf., of the dress (cf. 1. ruga, B.), to become wrinkled or rumpled: vide palliolum ut rugat, Plaut. Cas. 2, 3, 30: pallium, id. Fragm. ap. Gell. 18, 12, 3.
  2. II. Act., to wrinkle any thing: frontem, Hier. Ep. 50, 2.
    Transf., to corrugate: testae (concharum) rugatae, Plin. 9, 33, 52, § 102.