/fag'euh suy toh"sis/ , n.
Physiol. the ingestion of a smaller cell or cell fragment, a microorganism, or foreign particles by means of the local infolding of a cell's membrane and the protrusion of its cytoplasm around the fold until the material has been surrounded and engulfed by closure of the membrane and formation of a vacuole: characteristic of amebas and some types of white blood cells. Cf. endocytosis, exocytosis, pinocytosis .
[ 1890-95; PHAGOCYTE + -OSIS ]