Answer: perturbation

AnswerCrossword Clue
perturbationthe action of perturbing
perturbationA deviation of a system, moving object, or process from its regular or normal state of path, caused by an outside influence
perturbationA cause of such anxiety or uneasiness
perturbationA slight alteration of a physical system, for example of the electrons in an atom, caused by a secondary influence
perturbationAnxiety; mental uneasiness
perturbationA minor deviation in the course of a celestial body, caused by the gravitational attraction of a neighboring body