etio-, aetio- +

(Greek: cause, causation, originating; that which causes or originates something)

aetiologizing, etiologizing
1. Studying or examining the causes or origins of diseases or disorders as determined by medical diagnosis.
2. Philosophical investigations of causes and origins of phenomena.
etiogenic
Being or arising from a cause; casual.
etiolated
1. To cause yellowing of plants left in the dark.
2. Blanched as a plant exposed to insufficient sunlight.
3. Describing skin pallor which exists after being deprived of sunlight.
etiolation
1. Paleness or pallor resulting from absence of light, as in people confined because of illness or imprisonment, or in plants bleached by being deprived of light.
2. The process of blanching, bleaching, or making pale by withholding light
etiologic
1. Pertaining to causes or origins.
2. In pathology, originating from; causal; such as, an etiologic agent.
3. A reference to etiology.
etiological, aetiological (British)
1. Relating to the philosophical study of causation.
2. A reference to the etiology of a disease; such as, "an etiological agent".
etiologist
1. Anyone who studies etiology or the science of cause.
2. Someone who strives to find the causes of diseases via research and various forms of medical investigations.
etiology, aetiology (British)
1. The study of causation.
2. Any study of causes, causation, or causality; as in philosophy, biology, or physics.
3. The study of the causes of diseases or medical disorders.
4. The cause or origin of a disease.

The word etiology is primarily used in medicine, where it refers to the science that deals with the causes or origins of diseases including the factors which produce or predispose toward a certain disease or disorder.

Today in medicine one often hears, or reads: "The etiology is unknown"; meaning: "We don't know the cause."

Aetiology is the preferred spelling in some countries, including the UK, whereas etiology, without an "a", is dominant in the United States.

etiopathic
A reference to the pathogenesis, or cause, of a disease.
etiopathological
1. Relating to specific lesions concerned with the cause of a disease.
2. A reference to research in the causes of an abnormal illness.
etiopathology
Pathogenesis or the mechanisms involved in the causes and developments of a disease.
etiopathy
Determining the cause of a disease or illness.
etiotropic
1. Directed against the cause of a disease.
2. A reference to a treatment or medication that destroys or inactivates the causal agent of a disease.