tropism

The turning or bending movement of an organism or a part of an organism in a particular direction in response to an external stimulus such as light or gravity.

In biology, growth, bending, orientation, or locomotion of organisms, or of parts of organisms, in relation to external agents.

In a stricter use, the growing or bending of organisms, or of parts of organisms, in relation to external agents.

Modification of the direction of growth, caused by some external influence, such as light; — sometimes used for motion of an organism toward or away from an external stimulus, more properly called taxis.

the turning of an organism in response to a stimulus, either towards or away from the stimulus

viral tropism, or which type of tissue supports a certain virus

an involuntary orienting response; positive or negative reaction to a stimulus source