Hover (3.5e Creature Ability)
From D&D Wiki
Hover is a mode of movement similar to flight, except that the hovering creature can not fly higher than its reach. Likewise, it cannot clear objects taller than its reach. A hovering creature is unimpeded by any form of terrain so long as it is sufficiently level to not possess outcrops taller than its reach. Creatures that hover do so with a certain level of maneuverability (see Fly), but they can always hover in place regardless of maneuverability.