| Noun | 1. | instability - an unstable orderdisorder - a disturbance of the peace or of public order | |
| 2. | instability - unreliability attributable to being unstable | |
| 3. | instability - a state of disequilibrium (as may occur in cases of inner ear disease)disequilibrium - loss of equilibrium attributable to an unstable situation in which some forces outweigh others | |
| 4. | instability - the quality or attribute of being unstable and irresoluteunsteadiness - the quality of not being steady or securely fixed in place ricketiness, shakiness - the quality of being unstable and insecure; "the shakiness of the present regime" | |