That does seem to vary with vehicles, my hybrid is so called as it can go on a road or in the field, all e-bikes require one to pedal, but is seems one does not need to have a direct link of pedals to wheels, but with other vehicles it means twin engined one electric and the other carbon based fuel. But the same method has been used to power railway engines and simply called diesel-electric, hybrid transport has been around for a long time, even a film made, called Two Mules for Sister Sara the mule is a hybrid between a horse and donkey, there have been many off-road vehicles called mules
View attachment 402125so suppose they must be hybrids! But a hybrid is basic a mixture where you have the worst of both systems.