etiology

1. The establishment of a cause, origin, or reason for something. (countable, uncountable)
2. The study of causes or causation. (countable, uncountable)
3. The study or investigation of the causes of disease; a scientific explanation for the origin of a disease. (uncountable)
4. A cause of disease or of any particular case of a disease (but see pathology § Usage notes). (countable)

Plural etiologies