Green’s Dictionary of Slang

neckinger n.

a cravat.

1597		T. Deloney Pleasant Hist. of Jacke Newberie (1633) ix K3: His Wife [...] would not foule her fingers, nor turne her head aside, for feare of hurting the set of her neckenger.
1652		Laughing Mercury 6-12 Oct. 115: Hans may ene draw his Sluices, or nooze himself in his Willow Neck-neckenger.
1864, 1867, 1870		Hotten Sl. Dict.
1886		N&Q Ser. 7 II 98: Neckinger is nothing more than neckerchief, but implies, I think, proximity to a place of execution.