Mechanical device and Propellor

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

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

Propellor noun - A mechanical device that rotates to push against air or water.

Mechanical device and propellor are semantically related. You can use "Mechanical device" instead a noun "Propellor".