What's the correct way to imply that a course is not taken online?
Two terms that can be used are:
- In residence (or "resident")
- Face-to-face
The term face-to-face is often used in educational literature (e.g., see this Google result).
The term traditional classroom or traditional classroom setting is used in scholarly writing to refer to that mode of content delivery. Other modes of delivery are the online setting and the hybrid setting.