Green’s Dictionary of Slang

1. tuberculosis.

1905		H. Green Actors’ Boarding House (1906) 86: She’s got the con.
1913–14		E. O’Neill The Web in Ten ‘Lost’ Plays (1995) 61: I went to a doc about a month ago. He told me I had the ‘con’ and had it bad.
1925		S. Lewis Arrowsmith 187: We call him for doctoring, not for bossing. Why, the damn’ fool said we ought to burn down our houses – said we were committing a crime if we had the con. here!
1934		(con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 274: Might he not die on a mattress grave from con in the charity ward of a hospital if he did not die in a prairie or doorway.
1946		Mezzrow & Wolfe Really the Blues 310: This is it, I really got the con; for once I won’t have to fake T.B.
1964		(con. 1920s–40s) in J.L. Kornbluh Rebel Voices 407: Miner’s con – silicosis.
1987		(con. 1920s) L. Redmond Emerald Square 49: And consumption, the ‘oul’ Con’ never let up and picked his victims at will.

2. a sufferer from tuberculosis.

1921		P. & T. Casey Gay-cat 302: Con — [...] one afflicted with tuberculosis.
1939		Howsley Argot: Dict. of Und. Sl.
1949		Monteleone Criminal Sl. (rev. edn).