WordWeb Online

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

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, worry

Encyclopedia: Niggling