n. Disorder; irregularity.n. n. Irregularity in disease, or in the functions.n. The state of disorder that characterizes nervous fevers and the nervous condition.n. Loss of coordination in the voluntary muscles, especially the limbs; an inability to coordinate voluntary muscle movements; it results in unsteady movements and a staggering gait. See also locomotor ataxia, an ataxia which occurs when attempting to perform coordinated muscular movements.