Abnormal sac in the body containing liquid (4)

I believe the answer is:

cyst

(Other definitions for cyst that I've seen before include "Abnormal sac formed on or in the body" , "Biological sac" , "Abnormal body sac containing fluid" , "Thin-walled cavity containing liquid" , "Abnormal body cavity" .)

I've seen this clue in The Guardian.

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.