'mischievousness' originates from English, formed by adding the noun-forming suffix '-ness' to the adjective 'mischievous' (itself formed from 'mischief' + '-ous').

'Mischievous' and 'mischief' came into English via Old French (e.g. Old French meschief meaning 'misfortune' or 'bad turn'); 'mischief' entered Middle English as 'meschief', 'mischievous' developed later by adding '-ous', and finally the abstract noun 'mischievousness' was formed by the '-ness' suffix.

Initially related to 'mischief' in the sense of misfortune or harm, the sense shifted over time toward 'playful wrongdoing' or 'naughtiness'; 'mischievousness' now commonly denotes playful troublemaking, though it can also imply petty malice.