- of, like, or characteristic of a beast; bestial, brutal, etc.
- Informal disagreeable; unpleasant
- Of or resembling a beast; bestial.
- Very disagreeable; unpleasant.
(comparative beastlier or more beastly, superlative beastliest or most beastly)
Most often used pejoratively. Bestial is more narrow, though also often used pejoratively.
From beast + -ly.