When the newspaper refused to admit that the story was false, the actor 'filed/initiated a lawsuit' against the publisher. [=the actor sued the publisher]
They agreed to pay $100,000 to 'settle a lawsuit'. [=to end a lawsuit before the court made a decision about it]
a complex 'lawsuit' [='suit'] that may take years to resolve
(..) Harry! I overheard Menken talking with one of our security's head. Before they destroyed the spiders, they had the venom extracted. What are you saying? That way they could comply with the lawsuits but still keep the data whenever it became useful. - Where is it? - Somewhere in the building. (..)2014 The Amazing Spider-Man 2