tropism

tropism /tro·pism/ (tro´pizm) the turning, bending, movement, or growth of an organism or part of an organism elicited by an external stimulus, either toward (positive t.) or away from (negative t.) the stimulus; used as a word element combined with a stem indicating the nature of the stimulus (e.g., phototropism) or material or entity for which an organism (or substance) shows a special affinity (e.g., neurotropism). Usually applied to nonmotile organisms.

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tro·pism (trpzm)

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.

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tropic, tro·pistic adj.

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tropism

a growth response in a nonmotile organism elicited by an external stimulus, and either toward (positive tropism) or away from (negative tropism) the stimulus; used as a word element combined with a stem indicating nature of the stimulus (e.g. phototropism) or material or entity for which an organism (or substance) shows a special affinity (e.g. neurotropism).