gulgul

from The Century Dictionary.

• noun A sort of chunam or cement made of pounded sea-shells mixed with oil, which hardens like stone, and is used in India to cover ships' bottoms. It is impenetrable by worms even when unprotected by copper.

from the GNU version of the Collaborative International Dictionary of English.

• noun 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun 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.