'askewness' originates from English, specifically formed from the adjective 'askew' plus the nominalizing suffix '-ness' (meaning 'state or quality').

'askew' developed in Early Modern English as a combination of a- (an old prepositional/prefix element) + 'skew' (a word meaning 'to turn or slope', from Old Norse skakka). Over time the adjective 'askew' acquired the noun-forming suffix '-ness' to produce 'askewness'.

Initially it described being 'on a skew' or 'turned aside'; over time it became used as the noun indicating the state or quality of being tilted or crooked, a meaning that has remained essentially the same.