Mechanical device and Vane

Mechanical device noun - Mechanism consisting of a device that works on mechanical principles.

Vane and mechanical device are semantically related. In some cases you can replace term "Vane" with "Mechanical device", this terms are similar.

Vane noun - Mechanical device attached to an elevated structure; rotates freely to show the direction of the wind.

Mechanical device and vane are semantically related. Sometimes you can use "Mechanical device" instead a noun "Vane".