Slim young swimmer (5)

I believe the answer is:

elver

(Other definitions for elver that I've seen before include "A baby eel" , "One may see one upriver" , "Young migratory fish" , "Immature fish" , "Young slippery fish" .)

I've seen this clue in the LA 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.