1. [19C] the vagina, esp. when seen as a means of making money; one of a number of terms pointing up the commercial potential of the vagina; the man also ‘places a deposit in it’.
2. [mid-18C; 20C+] (Aus./US black/campus) money, one’s fortune.
3. [1900s–40s] (US black) the lavatory; esp. visit the bank, take a trip to the bank.
4. (US prison) a solitary confinement cell [the prisoner is secure as ‘money in the bank’].
[1990s+] (US black) to make money.
SE in slang uses
[1960s+] (drugs) depressants.
[1900s] (US Und.) a bank robber.
[mid-19C] (US) a banknote.
[1990s+] a fig. ‘bank’ on which ‘rubber’ cheques are drawn.
[1930s+] (US prison) to place an inmate in the punishment cells.
[late 19C+] to take for granted, to assume as a certainty.
[1900s–50s] (N.Z.) perfectly satisfactory, perfectly happy.