15 letters · 19 points in Scrabble
noun the folding in of an outer layer so as to form a pocket in the surface
noun (biology) growth in the surface area of a cell by the deposit of new particles between existing particles in the cell wall
originBorrowed from French intussusception, or directly from Latin intussusceptiō, from intus (“within”) + susceptiō (“susception”).
Etymology from Wiktionary, CC BY-SA 3.0