'roguishness' originates from English, specifically from the adjective 'roguish' plus the suffix '-ness' (used to form nouns denoting a state or quality).

'roguish' developed from the noun 'rogue' (English, c.16th century). 'Rogue' came into English by the 1500s (original source uncertain, perhaps from French or dialectal formations), and the adjective 'roguish' arose by adding the adjectival suffix '-ish' in the 17th century; 'roguishness' followed as a noun-forming construction.

Initially the root 'rogue' primarily meant 'a dishonest or vagrant person'; over time the derived adjective 'roguish' gained a secondary, milder sense of 'mischievous' or 'playfully dishonest', and 'roguishness' now covers both the mischievous and the deceitful senses.