1. very unpleasant or disagreeable
Usage: informal
2. resembling or characteristic of a beast; brutal or savage

1. extremely; very
Usage: informal; chiefly British

Examples

• The weather has been beastly all week.
• He showed beastly behavior toward his younger brother.
• It’s beastly cold outside today.
• The villain’s beastly cruelty shocked everyone.
• She was beastly tired after the long journey.
• His beastly temper made him difficult to work with.
• The food at that restaurant was absolutely beastly.