What is the meaning of Niggle?

A minor complaint or problem.

Small, cramped handwriting.

To trifle with; to deceive; to mock.

To use, spend, or do in a petty or trifling manner.

To dwell too much on minor points or on trifling details.

To fidget, fiddle, be restless.

To walk with short steps.

Source: wiktionary.org