Main Entry: tro·pism

Pronunciation: \ˈtrō-ˌpi-zəm\

Function: noun

Etymology: International Scientific Vocabulary -tropism

Date: 1899

1 a : involuntary orientation by an organism or one of its parts that involves turning or curving by movement or by differential growth and is a positive or negative response to a source of stimulation b : a reflex reaction involving a tropism
2 : an innate tendency to react in a definite manner to stimuli; broadly : a natural inclination : propensity <encouraged his tropism toward the theatrical — John Updike>

— tro·pis·tic \trō-ˈpis-tik\ adjective