saying something can hover usually implies that it can have a ground speed of 0 at an air speed of 0. If you leave out the air speed requirement then anything that can fly can hover
That doesn’t make sense. If something only hovers at air speed zero along with ground speed zero, then as soon as any wind whatsoever picks up, then that something is no longer hovering by your definition, even if it maintains the same place in the air. Hovering means to stay in the same place in the air. It doesn’t say anything about air speed, which is the delta between wind speed and ground speed.
