(transitive) The action of identifying the cause of a chain of events which leads to an outcome or effect of interest. To root cause something's root cause does not necessarily imply the use of root cause analysis (RCA).

(idiomatic) An initiating cause of a chain of events which leads to an outcome or effect of interest.

(intransitive) To cause controversy, or raise a disturbance.

(law) An event which, in a natural and continuous sequence, unbroken by any efficient intervening cause, produces an injury, and without which the injury would not have occurred.

(law) the case title for a cause of action/lawsuit; a description of the parties involved, such as Johnson v. Smith.

(chiefly US) Alternative form of cause célèbre

(US, law) The standard by which a police officer may make an arrest or conduct a personal or property search, based on the likelihood of a criminal act etc.

(law) A condition under which one party would be entitled to sue another. / (law) A civil lawsuit.

(medicine) A cause for an effect in a system that is not a constituent of that system, especially causes of personal health problems or death, such as poison, weapon wounds, or accident.

(law, England, Wales) In English law, to argue against the confirmation of a provisional order or judgment.