USUKAustraliaCanadainformalcolloquial
- With great energy, intensity, or ferocity; extremely vigorously.
USUKAustraliaCanadainformal
- With relentless or obsessive determination; uncontrollably driven to pursue or perform something.
USUKAustraliaCanadaneutral
- Resembling a demon in appearance or manner; terrifying, wild, or malevolent in look or behavior.