Starter or solenoid ?

First off turn over and crank are identical terms when it starts it's referred to as fires or starts. Up until the mid to late 1920s cars had a hand crank instead of an electric starter and this "Crank" was used to "turn" the engine over to start it, thus turning the engine over and cranking it are the same thing. The starter has a "Bendix" gear which is an inertial device to kick the starter out of mesh when the engine starts. What you describe sounds like a bad bendix.