A company that designs fonts. In the past they cast said fonts in metal to create movable type, a foundry is a place where metal is melted and cast into various forms. A font foundry was thus a place that made the type for printing presses.
It's a ton of work to design a font. Any designer can do it, not any designer can do it well. It's a very small niche of overall design. That led to a few companies specializing in font design, and predictably private equity firms have been buying them out & raising prices. Customers will switch away, but this creates unexpected work to do so some might end up paying at least for a while.
