From mischieve + -ing.
mischieving (plural mischievings)
- (now Scotland) The causing of damage or terror; rampaging. [from 15th c.]
- 1932, Lewis Grassic Gibbon, Sunset Song:
- And it ate up sheep and men and women and was a fair terror, and the King had his heralds cry a reward to whatever knight would ride and end the mischieving of the beast.