Express statements of resistance in French and English (3-4)

I believe the answer is:

non-stop

I'm a little stuck... Click here to teach me more about this clue!

'express' is the definition.
Both the definition and answer are adverbs. Perhaps they are linked in a way I don't understand?

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for non-stop that I've seen before include "continuously" , "Uninterrupted" , "Ceaseless" , "Continuous" , "Round-the-clock" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app