root cause

root cause (plural root causes)

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

root cause (third-person singular simple present root causes, present participle root causing, simple past and past participle root caused)

1. (idiomatic) 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).