Green’s Dictionary of Slang

1. (Aus./US) a derog. term for a Chinese person.

[1820		‘The Joss and his Folly’ in Queen’s Matrimonial Ladder D: The owner himself – an old fat Mandarin [...] sits in his China Shop, like a large Joss].
1891		J.A. Riis How the Other Half Lives 92: Between the tabernacles of Jewry and the shrines of the Bend, Joss has cheekily planted his pagan worship of idols, chief among which are the celestial worshipper’s own gain and lusts.
1938		X. Herbert Capricornia (1939) 130: Damn the old joss!
1957		D. Niland Call Me When the Cross Turns Over (1958) 10: He was four, built like a joss.

2. an admiral individual.

1890

Rogers & Durandeau [perf. Charles Coburn] ‘Come Where the Booze is Cheaper’ 🎵 Come where the boss is a bit of a joss! / Come to the pub next door!

3. (Aus.) a boss, a manager.

1894		Truth (Sydney) 24 June 1/4: There’s Chitterlings of Hamfat crowd, / A Joss among the jossages.
1901		W.A. Sun. Times (Perth) 28 July 1/1: A boss-joss journalist of Perth has succumbed to the winsome wink of a local grass widow.
1904		Sun. Times (Perth) 21 Aug. 1/1: The Deutscher boss pathetically appealed to his pen-drivers to say that the statements were wrong [...] the joss and his juggins now practice great secrecy in going to their book-keeping lessons.
1907		Sun. Times (Perth) 2 June 4/8: [of an Italian] The cook-shop boss-joss got wildly excited.

4. see josser n.⁴ (1)