putty
n. B2 Upper Intermediate US //ˈpəti// UK //pˈʌti// put·ty
n. a soft, sticky substance that you press into a hole to fill it. You usually use it to fix cracks in walls or to hold glass in a window frame.
n. a soft, pliable material used for sealing, filling, or holding objects in place. Often refers to a mixture of chalk or gypsum with linseed oil.
I used putty to fix the small crack in the wall.
Before hanging the new picture frame, he applied a thin layer of putty to the nail holes to make the surface smooth.
The artisan carefully mixed the oil-based putty to ensure it would harden evenly, providing a durable seal for the stained-glass window.
Borrowed from French potée (“polishing powder", originally "the contents of a pot, potful”), from French pot (“pot”). More at English pot.