CL

centiliter, centilitre, cl

(noun) a metric unit of volume equal to one hundredth of a liter

chlorine, Cl, atomic number

(noun) a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)

Source: WordNet® 3.1