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'.
caustic=it CAUSes your TIssues destroy!
The stinging sunburn I got CAUSed an involuntary TICk in my arm.