'nastiness' originates from English, specifically formed from the adjective 'nasty' plus the suffix '-ness' (a noun-forming suffix meaning 'state or quality').

'nasty' was first recorded in early 17th-century English; 'nastiness' developed later by combining 'nasty' with the productive suffix '-ness' to denote the state or quality of being nasty.

Initially, 'nasty' meant 'foul, unpleasant, or offensive', and over time that core sense was preserved; 'nastiness' has retained the meaning 'the quality of being nasty' while extending to related senses such as meanness or severity.