1. to act in response to or in opposition to a previous action
Usage: rare
2. to have a retroactive effect; to apply to past events or situations
Usage: legal; formal

Examples

• The new policy retroacts to cover all cases from the previous year.
• The court ruled that the law retroacts to January 1st.
• The company retroacts its benefits policy to include former employees.
• The regulation retroacts to affect contracts signed last month.
• The amendment retroacts to validate previous decisions.
• The insurance coverage retroacts to the date of enrollment.