Is it farther or further?
1670s, variant of dialectal skiver (1660s), perhaps from a Scandinavian source, cf. Old Norse skifa "a cut, slice" (of bread, etc.), Swedish skifer "a slate," which are related to shiver (n.1) "small piece."
1701, from the noun. Related: Skewered; skewering.
late 15c., "to turn aside" (intransitive), from Old North French eskiuer "shy away from, avoid," Old French eschiver (see eschew). Transitive sense of "turn (something) aside" is from 1570s. Meaning "depict unfairly" first recorded 1872, on notion of being "give oblique direction to," hence "to distort, to make slant." Statistical sense dates from 1929. Related: Skewed; skewing. The adjectival meaning "slanting, turned to one side" is recorded from c.1600, from the verb; noun meaning "slant, deviation" first attested 1680s.