Mosaic paste (5)

I believe the answer is:

grout

(Other definitions for grout that I've seen before include "Tile mortar" , "Tile fixer" , "plaster" , "Fill the cracks" , "Filling for joints between tiles" .)

I've seen this clue in The Mirror.

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.