Green’s Dictionary of Slang

a courtesan, a high-class prostitute, also attrib.

1863		Empire (Sydney) 17 Mar. 2/6: [from Dly Telegraph, London]The famous, or rather infamous, Cognita, or Anonyma, or Perdita, or Lucífera, or Diavoletta, as [...] euphemism may call the creature, [...] has levanted.
1864		G.A. Sala Quite Alone I 2: Is that Anonyma driving [...] and a groom with folded arms behind her? Bah! there are so many Anonymas now-a-days. If it isn’t the Nameless One herself, it is Synonyma.
1867		Gippsland Times (Vic.) 1 Aug. 4/1: healine] A Parisian Anonyma A lady, supposed to be a Javan, is now setting Paris by the ears.
1870		Hotten Sl. Dict.
1870		Record (Emerald Hill, Vic.) 25 Aug. 5/1: There is a constant outcry against-the ‘anonyma’ class and their irregularities — their immoralities, and whenever some unfortunate incident reveals the secrets of their inner life to the public gaze there is a great howl of execration.
1871		Sydney Morn. Herald 17 Mar. 6/3: [from Times, London] Paint and chignons, slang and vaudevilles, knowing ‘anonymas’ by name, and reading doubtfully moral novels.
1879		London Life 28 June 7/1: Being usually rich men, their domestic relations do not suffer by their profligate extravagance in the saloons of ‘Anonyma’.
1882		N.Y. Mercury in Ware (1909) 8/2: She could kick higher in the can-can than any anonyma there.
1885		Bowral Free Press (NSW) 4 July 4/2: [T]here are many samples of ladies who hang on the skirts of society, and pick up scandal in the shops [...] and the half-world has its representatives—nothing of Phryne or Lais about these however; Anonyma here [i.e. parading Collins St. Melbourne] is ignorant and vulgar.
1895		C. Crowe Aus. Sl. Dict 4: Anonyma, a lady of the demi-monde.
1900		R.H. Savage Brought to Bay 37: Hawtrey piloted the innocent cowboy out of the evening crowd of anonymas.
1909		J. Ware Passing Eng. of the Victorian Era 8/2: Anonyma (Soc., 1862). A name given to women of gallantry in an article in the Times commenting on a well-known Phryne of that day. The word lasted many years and came to be synonymous with a gay woman.
1923		J. Manchon Le Slang.