Plain English Meaning
How willing an airplane is to settle back to where it was after something nudges it off course, like a bump of turbulence or a brief control input.
Full Definition
The inherent tendency of an airplane, after being disturbed from a steady flight condition, to return to that original condition without pilot input. Stability is described along three axes (longitudinal, lateral, and directional) and in two forms: static stability (the initial response to a disturbance) and dynamic stability (the behavior of that response over time).
Context Anchor
Encountered when learning how an airplane handles, how it responds to control inputs, and how it behaves after turbulence or small disturbances.