Green’s Dictionary of Slang

1. (US) a sufferer from tuberculosis.

1921		Dos Passos Three Soldiers 30: ‘Look at me . . . t.b.,’ said the lanky man.
1931		D. Runyon ‘The Lily of St. Pierre’ in Runyon on Broadway (1954) 141: She strikes me as a t.b.
1942		C. Himes ‘Lunching at the Ritzmore’ in Coll. Stories (1990) 16: Drifters and hopheads and tbs’ and beggars and bums and bindle-stiffs.

2. (US) a confidence trickster [tuberculosis = consumption, abbr. = con = confidence-man].

1933		Ersine Und. and Prison Sl.
1950		Goldin et al. DAUL 220/2: T.B. 1. A confidence man.