Green’s Dictionary of Slang

narp n.¹

a shirt.

1839		H. Brandon in Miles Poverty, Mendicity and Crime; Report 164/1: Narp, a shirt.
1847		G.W.M. Reynolds Mysteries of London III 85/1: Six snooze-cases, three narps, and a blood red fancy .
1859		Matsell Vocabulum.
1864, 1867, 1870		Hotten Sl. Dict.
1882		Sydney Sl. Dict. (2 edn) 6: Mill Toy - A Shirt. Also, Narp.