verb (used with object), sued, su·ing. to institute a process in law against; bring a civil action against: to sue someone for damages. to woo or court.

How do you spell suit as in lawsuit?

a case in a court of law involving a claim, complaint, etc., by one party against another; suit at law.

Why is it called suing?

Each party is usually represented by a lawyer. That means that the lawyer will talk to the judge for the party. The party that starts the lawsuit is called the plaintiff because they are complaining about something the other side has done. This is also called "suing", or to "sue".