Possible Clues:

• When doubled, a taunt
• Equivalent of neener
• Gloating word usually repeated
• When repeated, a taunt
• Taunting word usually repeated
• When repeated, a child's taunt
• When repeated, a song-like taunt
• Taunting syllable that's usually repeated
• Gloater's syllable
• When repeated, an obnoxious taunt