Some vegetable leaves that are eaten are lettuce, spinach, and kale.
Vegetable
greens
An artichoke.
potato's and other such vegetables
vegetable oil
to steam vegetable and other stuff like other vegetables.
its a fruit because it has seeds
No more than any other vegetable.
vegetable oil and a load of other stuff
An edible plant is a vegetable.
Olive oil is a vegetable oil. You can often substitute other vegetable oils, but only experience, or a knowledgeable person can tell you it that will work for a particular recipe.