geotropism

• POS: Noun
• HYPHEN: ge=ot=ro=pism

CIDE DICTIONARY

geotropism, n. [Gr. ge`a, gh^, the earth + to turn.].

 A disposition to turn or incline towards the earth; the influence of gravity in determining the direction of growth of an organ.  [1913 Webster]
" In plants, organs which grow towards the center of the earth are said to be positively geotropic, and those growing in the opposite direction negatively geotropic. In animals, geotropism is supposed by some to have an influence either direct or indirect on the plane of division of the ovum."  [1913 Webster]

OXFORD DICTIONARY

geotropism, n. plant growth in relation to gravity.

Idiom

negative geotropism the tendency of stems etc. to grow away from the centre of the earth. positive geotropism the tendency of roots to grow towards the centre of the earth.

Derivative

geotropic adj.

Etymology

GEO- + Gk tropikos f. trope a turning f. trepo to turn