To carry on a lawsuit by judicial process.
Example:
If the company chooses to litigate, it may give the protesters the chance to make their points even more effectively in the courts and newspapers.
Litigation has become almost a way of life in America, where there are many more lawyers than in any other country on earth. In this increasingly litigious society, the courts have been overwhelmed with petty disputes. Television has responded to the trend by producing heroes like Judge Wapner of People's Court, a man who can show litigants the absurdity of their case while rendering a just verdict. (The Latin litigare includes the root word lit, "lawsuit," and thus means basically "to drive a lawsuit.")