What does tropism mean?
Tropism is a noun with a precise biological meaning and a useful figurative extension. In biology, it names the directional growth response of an organism to an external stimulus. A plant may show positive phototropism by growing toward light, while roots commonly display positive geotropism by growing toward gravity. The term can also describe a pronounced tendency in people or organizations, such as an inclination toward innovation or a preference for a particular approach. In figurative use, tropism generally suggests a recurring, almost systematic disposition rather than a single isolated preference. It is related to the same Greek root found in words such as tropic, tropical, and trope. The word is most often encountered in scientific writing, but its broader sense can add precision and literary emphasis when describing a defining tendency.
nounIn biology, a tropism is a directional growth response by an organism to an external stimulus, such as light, gravity, water, or chemicals. By extension, it can mean a natural tendency or disposition toward a particular course of action or interest.
- A directional growth response of an organism to an external stimulus, especially in plants.
- A natural or habitual tendency toward a particular interest, attitude, or course of action.
"The young shoot displays a positive tropism, bending toward the light."
"The young shoot displays a positive tropism, bending toward the light."
"The survey revealed a tropism toward practical problems rather than abstract theory."
Used when referring to multiple biological responses or multiple figurative tendencies.
"The researchers compared the growth tropisms of roots and shoots under different lighting conditions."
Plants turn toward light and roots grow toward gravity because of tropisms—built-in directions written into their biology.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does tropism come from?
Tropism entered English through French tropisme, a term derived from Greek tropos, meaning “turn” or “direction.” It was adopted in biology to describe the directional growth of organisms in response to external influences. Its figurative use developed from the idea of a characteristic orientation or turning tendency.
Related word forms
How tropism is actually used
The biological sense is chiefly scientific and especially common in botany. The figurative sense is formal and less frequent, usually describing a strong or characteristic tendency.
Easily confused with tropism
A tropism is a directional biological response or a figurative tendency, whereas a trophy is a prize or award.