A process of taking in fluid together with its contents into the cell by forming narrow channels through its membrane that pinch off into vesicles, and fuse with lysosomes that hydrolyze or break down contents.
It is the process of cells to ingest extracellular fluids (ECF) or the surrounding fluid, but not very specific in the substances or dissolved particles that it absorbs.
Word origin: pin: G. pín(ein) to drink + cyte: G. kutos, hollow vessel + -osis: expressing state or condition.
Related forms: pinocytotic (adjective).
Synonym: cell-drinking, fluid endocytosis.
See also: endocytosis, plasma membrane.