Sheetmetalworld.com has compiled a comprehensive glossary for the sheet metal and general manufacturing market. If we're missing some terms please feel free to use the Contact form.
Another useful glossary is the CAD CAM and Nesting glossary.
Joining two pieces of material by applying heat, pressure, or both. Sometimes this will be with or without a filler material. The join is produced through fusion/recrystallisation across the interface.