Green’s Dictionary of Slang

1. a man.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1873		Sl. Dict.
1882		Sydney Sl. Dict. (2 edn) 6: Nam - A man.
2001		J. Burkardt ‘Back Sl.’ Wordplay 🌐 nam: man.

2. a policeman.

1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1864, 1867, 1870		Hotten Sl. Dict.
1926		Derby Dly Teleg. 7 Apr. 3/3: Among other slang terms for police-men are rozzers, cossacks, frog; raw lobster, M.P. (member of police), nam.