aitio-, -aitio +

Descriptive of reactions and movements caused by an external agent, a stimulus, or some force: The vaccination that Dr. Smith gave Jim produced an aitiogenic immune response in Jim's body.

1. A tale devised to explain the origin of a religious observance: An aition was a myth or story depicting the beginning of a sacred custom or tradition. in Ancient Greece.

Sometimes aition was used for a myth that explains an origin, particularly how an object or custom came into existence. 2. The most general Greek term for a cause or a responsibility: Aition was used by Aristotle, especially in reference to any one of the four kinds of answer it is legitimate to give in response to any "Why . . . ?" question.

A change in direction or bending caused by external forces: An aitionastic respond can be explained by the curvature of part of a plant stimulated by a widely spread or a scattered stimulus, like the flower of the sunflower changing position depending on the course of the sun.

A reference to growth patterns and other phenomena imposed by the environment: A condition of aitionomic process could be observed in some plants that were gradually dying out due to the increase in smog and air pollution in the region.

A reference to any movement that comes from an external stimulus: When the wind took up speed, Jill noticed the aitiotropic swaying of the tall trees produced by the strong gusts that howled loudly outside her home.

Any tropism (movement, response) resulting from an exogenous (external) stimulus: Nils read about aitiotropism in his book and realized that this phenomenon could have referred to the situation of the blasting storm that recently destroyed the roof of his garage! .