Wiktionary
n. (context idiomatic English) An initiating cause of a chain of events which leads to an outcome or effect of interest.
Wikipedia
A root cause is an initiating cause of either a condition or a causal chain that leads to an outcome or effect of interest. Commonly, root cause is used to describe the depth in the causal chain where an intervention could reasonably be implemented to improve performance or prevent an undesirable outcome.
In plain English a "root cause" is a "cause" (harmful factor) that is "root" (deep, basic, fundamental, underlying, initial or the like).
The term root cause has been used in professional journals as early as 1905.
Paradies (2005) has defined a root cause as follows: "The most basic cause (or causes) that can reasonably be identified that management has control to fix and, when fixed, will prevent (or significantly reduce the likelihood of) the problem’s recurrence."
Fantin (2014) describes the root cause as the result of the drill down analysis required to discover which is the process that is failing, defining it as "MIN Process" (meaning a process that is Missing, Incomplete or Not followed)
About Root-Cause discovery, see Root cause analysis.
Usage examples of "root cause".
Their dogma was that the Iraqi regime was the root cause of nearly every evil to befall the United States (from Arab-Israeli violence to international terrorism), while the Iraqi people were waiting to rise up against Saddam and would do so if the United States demonstrated that it was serious about overthrowing him.
We both agree that the root cause for most of this nation's inner problems lies in the home.
That mind- created duality is the root cause of all unnecessary complexity, of all problems and conflict in your life.
The root cause of this malfunction is the fantastically low moisture content of the atmosphere on this planet.
Many theorists believe both barriers stem from the same root cause.
And secondly, I'm not convinced that it is the giga-conductor which is the root cause of the blitz.
Pleasants disappearance, since her mother hadnt known the man existed, but she was still part and parcel of the root cause.
The root cause of the problems began the day of the first rumor that we had been contacted by aliens.
The possibility that his own feelings toward Franklin could have the same root cause seems not to have entered his mind.
The effect on national politics would be profound, and as was perhaps inevitable, the root cause was the revolution in France.