Green’s Dictionary of Slang

1. (Aus./US) a profession, usu. that of the theatre [pron. of abbr. SE profession].

1884		Nat. Police Gaz. (NY) 19 Jan. 2/4: [of journalism] ‘I hope you will keep my name out of the paper [...] I belong to the perfesh, you know’.
1885		Bulletin (Sydney) 17 Jan. 9/1: [Some] tell us she has a sweet contralto voice of great flexibility, power, and range. If so, and that she decides (which is almost certain) in taking to the ‘perfesh,’ she should be heard again. [Ibid.] 24 Jan. 10/4: Admit this true! escape this mesh, / The public will see fair; / Say cricket is your sole ‘perfesh,’ / And you can’t live on air.
1894		Truth (Sydney) 7 Oct. 2/6: The open-air fete, in aid of members of the ‘perfesh’ who are suffering from the prevalent depression, takes place [...] on Thursday week.
1900		Bulletin (Sydney) 16 Jun. 12/4: There is to-day hardly a theatrical family of note that has not had a divorce in it. When members of the ‘perfesh.’ are not working, they appear to put in time getting divorced. Decrees nisi are plentiful as grease-paint.
1902		Sun. Times (Perth) 8 June 8/2: Lots of people are talking of going Johannesburg-wards [...] Particularly the brokers, who all seem to have satisfied themselves [...] that the Rand is going to be a regular Tom Tiddler’s for their ‘perfesh’.
1905		Sporting Times 1 Apr. 2/3: When Corbett gits the gloves on as the melancholy Dane, / You bet the whole perfesh. will up an’ follow in his train.
1931		Irwin Amer. Tramp and Und. Sl.

2. (US tramp) a veteran tramp [pron. of abbr. SE professional].

1931

Irwin Amer. Tramp and Und. Sl. 143: Perfesh.–A professional, experienced tramp. Tramp life in general. [...] Perfesh.– [...] Any expert in some particular line.