A legal action originating with a complaint where a plaintiff claims a defendant failed to perform a legal duty owed to them, resulting in harm to the plaintiff.
Merriam-Webster Online Dictionary
lawsuit (noun) a suit in law a case before a court
Merriam-Webster Online Thesaurus
lawsuit (noun)a court case for enforcing a right or claim
SYNONYMS:
action, proceeding, suitRELATED WORDS:
litigation; case, cause, complaint; counterclaim, countersuit, cross action, cross-claim