de·range / diˈrānj/ • v. [tr.] [usu. as adj.] (deranged) cause (someone) to become insane: a deranged man. ∎ throw (something) into confusion; cause to act irregularly: stress deranges the immune system. ∎ archaic intrude on; interrupt: I am sorry to have deranged you for so small a matter.DERIVATIVES: de·range·ment n.