noun \ˈk-sən\

Definition of AUXIN

:  any of various usually acidic organic substances that promote cell elongation in plant shoots and usually regulate other growth processes (as root initiation): as
a :  indoleacetic acid
b :  any of various synthetic substances (as 2,4-D) resembling indoleacetic acid in activity and used especially in research and agriculture
aux·in·ic \k-ˈsi-nik\ adjective

Origin of AUXIN

International Scientific Vocabulary, from Greek auxein to increase — more at eke
First Known Use: 1933


noun \ˈk-sən\   (Medical Dictionary)

Medical Definition of AUXIN

: an organic substance that is able in low concentrations to promote elongation of plant shoots and usually to control other specific growth effects; broadly : plant hormone


noun    (Concise Encyclopedia)

Any of a group of hormones that regulate plant growth, particularly by stimulating cell elongation in stems and inhibiting it in roots. Auxins influence the growth of stems toward light (phototropism) and against the force of gravity (geotropism). Auxins also play a role in cell division and differentiation, fruit development, the formation of roots from cuttings, the inhibition of lateral branching, and leaf fall. The most important naturally occurring auxin is beta-indolylacetic acid.


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