A state of restlessness and agitation, often accompanied by a distressing sense of oppression or tightness in the stomach.
An unpleasant state of mental uneasiness, nervousness, apprehension and obsession or concern about some uncertain event.
An uneasy or distressing desire (for something).
Agitation; the state of being perturbed
Variation in an orbit due to the influence of external bodies
A small change in a physical system, or more broadly any definable system (such as a biological or economic system)