neutral static stability
i. In meteorology, it is that condition in which the observed lapse rate is equal to the dry adiabatic lapse rate. A parcel of dry air will remain at its new level once it is pushed up because its temperature will be the same as that of the surrounding air.
ii. In aerodynamics, it means that an aircraft will tend to stay in its most recently commanded attitude or condition, without oscillations, and it will neither tend to return to its previous state or diverge from its new attitude. Also called neutral equilibrium or neutral static stability.