For a satellite orbiting the Earth, an orbit in the equatorial plane.
An orbit in the plane of the equator.
An orbit with a plane parallel to the earth's equator.
The satellite flies along the line of the Earth's equator. Equatorial orbits can be useful for satellites observing tropical weather patterns, as they can monitor cloud conditions around the globe.
Equatorial orbit is an orbit with inclination to the plane of reference (i.d. equator) equal to zero.