Very harsh, as comments
I believe the answer is:
acid
(Other definitions for acid that I've seen before include "It is neutralised by alkali" , "Acerbic" , "Tart, sour" , "So-called drug" , "Corrosive substance" .)
I believe the answer is:
acid
(Other definitions for acid that I've seen before include "It is neutralised by alkali" , "Acerbic" , "Tart, sour" , "So-called drug" , "Corrosive substance" .)