per·turb / pərˈtərb/ • v. [tr.] 1. (often be perturbed) make (someone) anxious or unsettled: they were perturbed by her capricious behavior | [tr.] they were perturbed that the bank had begun switching some of its problem loans. 2. subject (a system, moving object, or process) to an influence tending to alter its normal or regular state or path: nuclear weapons could be used to perturb the orbit of an asteroid.DERIVATIVES: per·turb·a·ble adj.per·tur·ba·tive / ˈpərtərˌbātiv; pərˈtərbətiv/ adj. (sense 2)per·turb·ing·ly adv.