WordNet (r) 3.0 (2006):

nose ring
    n 1: a ring worn on the nose as an ornament or on the nose of an
         animal to control it

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "nose ring":
   anklet, armlet, band, bangle, beads, belt, bijou, bracelet,
   breastpin, brooch, chain, chaplet, charm, chatelaine, cincture,
   cingulum, circle, collar, collarband, coronet, crown, diadem,
   earring, ecliptic, equator, fascia, fillet, finger ring, fob, gem,
   girdle, girt, girth, great circle, hoop, jewel, locket, neckband,
   necklace, pin, precious stone, quoit, rhinestone, ring, stickpin,
   stone, tiara, torque, wampum, wristband, wristlet, zodiac, zone