phosgene

noun

Etymology: From Ancient Greek φῶς (phôs, “light”) + -gene, due to its first synthesis involving sunlight.

1. carbonyl chloride

   ““‘Poison gas’?” A new one on Lew. But Dr. De Bottle had taken on a somber look. “Phosgene.””

   “Remote and cold, H-276 is nevertheless of interest due to phosgene gas in its thick chlorine atmosphere. This could indicate primitive chlorine-based life. However, no detailed study has been completed.”