Chlorine (noun)

1. A chemical element with the symbol Cl and atomic number 17, a halogen.
2. A pale yellow-green gas that is highly reactive and is used in many industrial and cleaning processes.

Origin:

From greek word "chloros" meaning "green" and "chlorine" meaning "pale green".

Examples:

1. Chlorine is used to disinfect swimming pool water.
2. The gas leaked from the tank was identified as chlorine.
3. Chlorine is a toxic gas, it can cause harm to human respiratory system.
4. Chlorine is added to the water supply to kill harmful bacteria.
5. The company uses chlorine to bleach their paper products.