Green’s Dictionary of Slang

nurse v.

1. [late 18C–19C] to cheat or swindle.

2. [mid-19C–1900s] for one omnibus to follow a rival closely so as to poach its passengers.

In phrases

at nurse

[late 18C–early 19C] for a person to be in the hands of (dishonest) trustees.

nurse the iron baby (v.)

[late 19C] (UK Und.) to be in prison.