Contrivance (noun)

A device, mechanism, or plan created for a specific purpose; an invention or scheme.

Origin:

Late middle english. from latin contrivare "plan, scheme", from con- + trivium "crossroads" (with reference to a scheme as a turning point in a career).

Examples:

1. The engineer designed a new contrivance to improve the efficiency of the machine.
2. The contrivance of the thief's plan was clever but ultimately unsuccessful.
3. The contrivance of the trap was ingenious.
4. The contrivance of the escape route was well thought out.
5. The contrivance of the voting system was criticized for being unfair.