/fos"jeen, foz"-/ , n. Chem.
a poisonous, colorless, very volatile liquid or suffocating gas, COCl 2 , a chemical-warfare compound: used chiefly in organic synthesis. Also called carbon oxychloride, carbonyl chloride, chloroformyl chloride .
[ 1805-15; phôs light (contr. of pháos ) + -genes -GEN ]