Phagocytosis is a process in which cells (called phagocytes) engulf [surround or cover] and digest foreign particles (such as bacteria or cellular debris) to protect the body from infections and remove waste materials. The word “phagocytes” refers to cells that can eat. For example, when a bacterium enters the body, phagocytes recognize it as foreign and engulf it, destroying the bacterium in the process.
Very Simple Definition:
Phagocytosis is a way that cells in our body eat and destroy harmful things like bacteria. When a harmful germ enters our body, special cells eat it up and get rid of it.