Fuel injection and Mechanical system

Fuel injection noun - Mechanical system to inject atomized fuel directly into the cylinders of an internal-combustion engine; avoids the need for a carburetor.

Mechanical system and fuel injection are semantically related. In some cases you can use "Mechanical system" instead a noun phrase "Fuel injection".

Mechanical system noun - A system of elements that interact on mechanical principles.

Fuel injection and mechanical system are semantically related. Sometimes you can replace phrase "Fuel injection" with "Mechanical system", this phrases are similar.