Is it under way or underway?
Both of these expressions exist in British English. They do, however, have different meanings.
This is used to mean that something is happening/going ahead.
- The project is now under way.
- It was not long before their journey was under way.
- They were under way in less than three hours.
This is an adjective (or describing word), meaning ‘occurring while in motion’.
- We are going to try underway refuelling.