gelatin

Etymology

Borrowed from French gélatine (“jelly, gel”), from Italian gelatina (“jelly, gel”), from gelare (“to freeze”), from Latin gelare (“to freeze”).

noun

1. A protein derived through partial hydrolysis of the collagen extracted from animal skin, bones, cartilage, ligaments, etc.
2. An edible jelly made from this material.
3. A thin, translucent membrane used as a filter for photography or for theatrical lighting effects.
   For both images I placed a Kodak 4.0 neutral-density gelatin filter over the lens to reduce the Sun's brightness. 2010 April, Frank Zullo, “Imaging Prehistoric Sunrises”, in Astronomy, volume 38, number 4, page 50