A naturally occurring substance similar to asphalt, pitch, or tar. It is a thick, sticky substance found naturally in the ground. People in ancient times used it like a type of glue or sealant.
Bitumen (or tar) was used for mortar when building the Tower of Babel (Genesis 11:3). It was also used to seal the reed basket in which baby Moses was hidden (Exodus 2:3). In Israel, the valley of Siddim had many bitumen pits. Some soldiers fell into them during Chedorlaomer's war against Sodom and Gomorrah (Genesis 14:10).
Bitumen is translated as “slime” in the King James Version.