from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Botany The tendency of growing parts, such as roots, to become oriented at right angles to the direction of gravitational force.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The tendency of plant organs, such as roots, to assume a position oblique or transverse to a direction towards the centre of the Earth.
from the GNU version of the Collaborative International Dictionary of English
- n. The tendency of organs (as roots) of plants to assume a position oblique or transverse to a direction towards the center of the earth.
from The Century Dictionary and Cyclopedia
- n. In botany, transverse geotropism; a turning in a direction at right angles to that of gravitation.
dia- + geotropism (Wiktionary)