Bonding two or more items together, where at least one is 3D Printed.
Sometimes we have to print jobs in several pieces, for reasons of build volume, or using different colours, or even different plastics.
Items can be glued together later using a variety of products, but what glue to use for different filaments. Also, sometimes we glue 3D printed parts to real-world parts as a repair, or because the final item contains both 3D Printed and other parts, like wood, plastics, metal, or fabric.
This is not about gluestick on the bed, that should be tagged adhesion