The Collaborative International Dictionary
Gulgul
Gulgul \Gul"gul\, n. [Hind. galgal.] A cement made in India from sea shells, pulverized and mixed with oil, and spread over a ship's bottom, to prevent the boring of worms.
Wiktionary
gulgul
n. A cement made in India from seashells pulverized and mixed with oil, and spread over a ship's bottom to prevent worms from boring into it.