Also, out of whack. Not properly adjusted, not working well, out of order. For example, This whole schedule is out of kilter with the rest of our projects, or The wheels on the trailer are out of whack. The first term, also spelled kelter, dates from the early 1600s and its origin is not known. The precise allusion of the variant, a colloquial term dating from the late 1800s, is also unclear. Possibly it relates to a whack, or blow, throwing something off, or some suggest, to wacky, that is, “crazy.”