caustic - Dictionary definition and meaning for word caustic
caustic soda is very common and its "harmful " for health if taken in large quantity....therefore caustic means harmful or burning. Since its a soda its somehow related with chemistry as well..
sounds like 'caution'... meaning, be careful, there is something..... that is corrosive... or... 'can cause corrosion'.
In medical terms 'cauterize' is burning or sealing the ends of blood vessels/nerves similar to destroying; As far as speech, talking about the holoCAUST can be harsh
caustic=it CAUSes your TIssues destroy!