adjective
Etymology: from present participle of niggle
1. : petty
impatient with small patterns and regular meters, which they find niggling and hampering — Louise Bogan
2.
a. : meticulous
being some niggling task, usually the preparation of a very careful drawing — Lancet
b. : overelaborate or feeble in execution
the brushwork trailed off in niggling strokes — Atlantic
• nig·gling·ly adverb