To disturb the regular order of; throw into confusion; disconcert; disarrange: as, to derange plans or affairs.To disturb the state, action, or functions of; put out of proper order or condition; disorder; unsettle: as, to derange a machine; his health is much deranged; to derange one's mind or reason.To disorder the mind of; unsettle the reason of, as a person.To disarrange, displace, unsettle, confuse, embarrass, discompose, disconcert.