n. [ L. perturbatio: cf. F. perturbation. ] 1. The act of perturbing, or the state of being perturbed; esp., agitation of mind. [ 1913 Webster ]
2. (Astron.) A disturbance in the regular elliptic or other motion of a heavenly body, produced by some force additional to that which causes its regular motion; as, the perturbations of the planets are caused by their attraction on each other. Newcomb. [ 1913 Webster ]
(n) activity that is a malfunction, intrusion, or interruption, Syn. disturbance, Example:the term `distress' connotes some degree of perturbation and emotional upset; he looked around for the source of the disturbance; there was a disturbance of neural function