Some sea-green water coming upriver (5)

I believe the answer is:

eagre

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

'coming upriver' is the definition.
The definition suggests a singular noun which matches the answer.

'some sea-green water' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'EAGRE' can be found hidden inside 'sea green water'.

Can you help me to learn more?

(Other definitions for eagre that I've seen before include "A tidal bore" , "river danger" , "High wave" , "The bore sounds keen" .)

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.