Support British on search for swimmer (10)

I believe the answer is:

ribbonfish

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

'swimmer' is the definition.
(ribbonfish is a kind of aquatic vertebrate)

'support british on search' is the wordplay.
'support british on' becomes 'ribbon' (I can't explain this - if you can you should believe this answer much more).
'search' becomes 'fish' (fishing is a kind of searching).
'ribbon'+'fish'='RIBBONFISH'

'for' is the link.

Can you help me to learn more?

(Another definition for ribbonfish that I've seen is " Long thin sea-dweller".)

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.