geotropism noun.
[dʒi:ǝ(ʊ)'trǝʊpɪz(ǝ)m] L19.[from GEO- + Greek tropē turning + -ISM.]Botany. The growth of part of a plant in response to gravity.
negative geotropism tendency (of stems etc.) to grow upwards.
positive geotropism tendency (of roots etc.) to grow downwards.
[TahlilGaran] English Dictionary ▲