I asked what you call it, not what is correct. :p
Motor oil
Motorcycle
Motor vehicle
Just havin some fun.
How about STP engine treatment that goes in the motor oil?

I'm in the electrical industry and always refer to electric Motors and Fuel powered engines. Technically an engine is really an Air pump which uses fuel to power it. The by product is transfered to reciprocal power much like the hydro force used to generate electricity at a dam.
Sorry for the tech crap I still sometimes call it a motor.

Can you put this in an engine?

It's just a big expensive lump of metal with a bunch O' parts all just trying their best to get out by thrashing around in there til one or more of them succeeds, usually about 12 hours before the start of a holiday weekend.

Is it called a rocket engine or rocket motor? No reciprocating mass but it does use fuel.
Why is a train driven by an electric motor piloted by an Engineer ? Shouldnt it be a Motoreer?

I call it a boat motor, but it is run on gas not electric, so it is technically an engine.
But someday it may be a motor run by batteries that are charged by an engine.... that will be my project for retirement.

An Engine run's a Motor, and turbines seem, to be the trend to run everything...

Why do you drive on a Parkway and park on a Driveway?

Engine

Same as above.

Motors are electric.

Engines run on fossil fuels.