WordWeb Online

1. Small and of little importance
   "a dispute over niggling details";
   - fiddling [informal], footling [informal], lilliputian [informal], little [informal], piddling [informal], piffling [informal], petty [informal], picayune [N. Amer, informal], trivial [informal], niggly [informal], piddly [informal]

1. Worry unnecessarily or excessively
   "don't niggle too much over the grandchildren--they are quite big now";
   - fuss, fret
    
2. Argue over petty things
   "Let's not niggle over pennies";
   - quibble, pettifog, bicker, squabble, brabble

See also: unimportant

Type of: argue, contend, debate, fence, sweat [N. Amer, informal], worry

Encyclopedia: Niggling