The Collaborative International Dictionary of English v.0.48:

Earring \Ear"ring`\, n.
   An ornament consisting of a ring passed through the lobe of
   the ear, with or without a pendant.
   [1913 Webster]

WordNet (r) 3.0 (2006):

earring
    n 1: jewelry to ornament the ear; usually clipped to the earlobe
         or fastened through a hole in the lobe

Moby Thesaurus II by Grady Ward, 1.0:

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