(theology, philosophy, sometimes capitalized) An initial cause from which all other causes and effects follow.

simple past tense and past participle of cause

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

(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).

In a causative manner / Regarding causation

(dated) Potassium hydroxide.

One who fights for the sake of fighting but has no clear goal to achieve.

plural of causal

(linguistics) Pertaining to any case that indicates the intention of achieving a specific final result. / Goal-oriented; purposeful as opposed to prescribed.

(grammar) The causal-final case. This case in the Hungarian language combines the causal case and the final case. It can express the cause of emotions (e.g. value someone for something) or the goal of actions (e.g. "kenyérért" for bread).