Cornwall-Devon border river (5)

I believe the answer is:

tamar

(Other definitions for tamar that I've seen before include "River and bridge which connect Devon and Cornwall" , "Devon-Cornwall boundary river" , "River of SW England" , "River in south-west" , "Plymouth river" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.