askew is probably from a- ('on') + skew, the latter from Old North French eskiuer ('to shun, avoid'), of Germanic origin; perhaps reinforced by Old Norse á ská ('on the skew'). Morphologically, the word is transparent as a compound: its parts remain visible in the modern spelling, while the older history of those parts supplies the deeper ancestry. In modern use, the adverb sense is "not straight or level; to one side, crooked", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as skew, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Old French eskiuer, which anchor the explanation in named linguistic material.