"the business of a banker," 1735, verbal noun from bank (v.1).
Entries linking to banking
bank v.1
"to act as a banker," 1727, from bank (n.1). As "to deposit in a bank" from 1833. Figurative sense of "to rely on" (i.e. "to put money on") is from 1884, U.S. colloquial. Related: Banked; banking; bankable.