the world > plants > part of plant > reproductive part(s) > flower or part containing reproductive organs > [noun] > parts of > petal > doubleness or doubling (2)
Botany. The condition of being flore pleno or double-flowered. Obsolete.
Botany. The filling up of the disk or cup of a flower with petals, by the conversion of stamens, nectaries, etc. into petals; the ‘doubling’ of a…