Did you mean exocytosis? if so, the definition is a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.
Exocytosis can be of any size, as long as it can fit in the cell.
In exocytosis a vesicle docks and fuses with the plasma membrane with the aid of a group of proteins called SNARE complexes.This will involve a specific SNARE complex on the vesicle side (called a v-SNARE) binding to a specific SNARE complex on the plasma membrane itself.
Endocytosis - the way in which cells take in food and other materials. The cells membrane wraps around the particle it needs on its outside, ingesting it. This then becomes trapped within a vacuole inside the cells cytoplasm where it is broken down, digested, and absorbed by enzymes.