Thermotropism

noun

1. The movement or growth of an organism toward or away from heat.
2. In biology, the bending or growing of organisms in relation to heat.
3. In botany, the phenomenon of curvature produced in a growing plant-organ by changes of temperature. Organs which curve toward the source of heat are called positively thermotropic, and those which curve away from the source of heat, negatively thermotropic.
4. The phenomenon of turning towards a source of warmth, seen in the growing parts of some plants.
5. Thermotropic movement of a plant or plant part in response to changes in temperature.