GO:0048550

Any process that stops, prevents, or reduces the frequency, rate or extent of pinocytosis. Pinocytosis is the process in which cells take in liquid material from their external environment; literally 'cell drinking'. Liquid is enclosed in vesicles, formed by invagination of the plasma membrane. These vesicles then move into the cell and pass their contents to endosomes. [GOC:go_curators]