As Jim says, an orbit would generally be a 360 degree continuous turn to rollout either doing whatever you were doing before or onto a specific track/heading. A hold would usually be a pre-published procedure at a given point. An ad-hoc hold can be done, and in giving it I’d specify: at what point (usually present position, but you could use a waypoint etc), inbound heading, turn direction and length of legs.
I think a hold having specific upwind and downwind legs is probably a big differentiator from an orbit, along with always returning to a fixed point.