merisis
/ˈmɛrɪsɪs/Botany. Now rare
noun
Growth of a plant which is due to an increase in the number of cells rather than to cell expansion.
Origin
1940s; earliest use found in Nature: a weekly journal of science. Either irregularly from ancient Greek μερίς part + -sis, or independently from meri- + -sis, perhaps after auxesis.