1. To petition (a court) for redress of grievances or for the recovery of what is a logical claim: "Joni's landlord has sued her for not paying her rent."
2. To institute proceedings against (a person or organization) for reparations for being wronged or injured.
3. Etymology: "continue, persevere", from Anglo-French suer, "follow after, continue"; from Old French sivre, later suivre, "pursue, follow after"; from Vulgar Latin sequere, "to follow"; from Latin sequi, "follow".