A linkup is a connection that joins two things so they can work together — especially two organisations, two machines, or two communication systems. A radio linkup lets people in different places talk on air; a business linkup is when two companies join for a project. It is the noun from the phrasal verb link up. The tone is everyday to news-and-tech, not fancy. Though actually, link already means a connection; linkup leans on the joining itself, the hook-up, as in “a satellite linkup at six”.