1. in an extremely hostile or bitter manner
2. in a way that spreads or develops rapidly and harmfully
Usage: often used in medical contexts

Examples

• The critic virulently attacked the new policy in his editorial.
• She spoke virulently against the proposed changes.
• The infection spread virulently through the population.
• He virulently opposed any compromise on the issue.
• The disease progressed virulently despite treatment.
• The debate became virulently personal and hostile.