Pronunciation: (nig'ul), [key]
—v.i., -gled, -gling.
1. to criticize, esp. constantly or repeatedly, in a peevish or petty way; carp: to niggle about the fine points of interpretation; preferring to niggle rather than take steps to correct a situation.
2. to spend too much time and effort on inconsequential details: It's difficult to be meticulous and not niggle.
3. to work ineffectively; trifle: to niggle with an uninteresting task.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.