1. The main or most important reason or source from which something originates or is produced
The primary cause of the accident was driver negligence.
A causa primária do acidente foi negligência do motorista.
2. In philosophy and theology, the original or fundamental cause that sets all other causes in motion
Aristotle argued that God is the primary cause of all existence.
Aristóteles argumentou que Deus é a causa primária de toda existência.
3. In medicine and science, the direct or root cause of a disease or phenomenon, as opposed to secondary causes
Smoking is the primary cause of lung cancer in this study.
O tabagismo é a causa primária do câncer de pulmão neste estudo.