Lewis & Short

ringor, rictus, 3, v. dep. n., to open wide the mouth, to show the teeth (very rare).

  1. I. Lit.: saltat ridens, ringitur, Pompon. ap. Non. 517, 30 (Com. Rel. p. 206 Rib.).
  2. II. Trop., to be vexed, angry; to chafe, snarl (the fig. borrowed from a growling dog): ille ringitur, tu rideas, Ter. Phorm. 2, 2, 27 Don.: ringeris quoties aliquem in fastis saepius legeris, Sen. Ep. 104, 9: sapere et ringi, Hor. Ep. 2, 2, 128; Sid. Carm. 23, 86.