Green’s Dictionary of Slang

irritatingly petty, intrinsically unimportant but time- and energy-consuming.

1631		A. Wilson The Swisser II i: Yee nigling Ticks you!
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1859		Hotten Dict. of Modern Sl. etc. 68: NIGGLING, trifling, or idling.
1864, 1867, 1870		Hotten Sl. Dict. [as cit. 1859].
1873		Sl. Dict.
1952		K. Amis letter 18 June in Leader (2000) 285: Naked they came, a niggling core of girls.
1954		B. Kiely Honey Seems Bitter 149: Pinning up a piece of paper is the miserable niggling modern way.