Crossword Genius

Aquatic parasite (5)

Ross

I believe the answer is:

leech

(Other definitions for leech that I've seen before include "Parasite - hanger-on" , "Old physician" , "Worm - sponger" , "Blood sucker" , "Annelid worm, used in medicine of old" .)

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.