Crossword Genius

Port ain't on River Thames? Primarily, it's the one used by Constable, for example!

Ross

I believe the answer is:

paint pot

I'm a little stuck... Click here to teach me more about this clue!
I've seen this clue in the Irish 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.