kilter
Chiefly in out of kilter: (good) condition, form, or order; fettle.
uncountable
[T]hey are either round-shouldered, knock-kneed, bow-legged, or parrot-toed; some are also badly cross-eyed. It seems as if they can see two different ways at the same time. Jack says they are lop-sided and out of kilter altogether.
Where it comes from
A variant of dialectal kelter (“good condition, order”), of unknown origin; possibly related to kilt (“to gather up (skirts) around the body”) (cognate with Danish kilte (“to tuck”)), or Scots kilt (“proper way of doing something, knack”) (probably from kilt (“a slope; a tilt”), possibly a variant of English tilt). In the 19th century, kelter was the more common form in the United Kingdom, while kilter was more common in the United States. Due to the influence of the latter, kilter is now the more prevalent form in all English varieties.
Adapted from the Wiktionary entry kilter (CC BY-SA 4.0).