tropism tro·pism (trō'pĭz'əm)
n.
The turning or bending movement of a living organism or part toward or away from an external stimulus, such as light, heat, or gravity.
| tropism (trō'pĭz'əm) Pronunciation Key
The growth or movement of a living organism or anatomical structure toward or away from an external stimulus, such as light, heat, or gravity. See also geotropism, hydrotropism, phototropism. tropistic adjective |