caus ‧ tic /ˈkɔːstɪk $ ˈkɒːs-/ BrE AmE adjective
[ Date: 1300-1400 ; Language: Latin ; Origin: causticus , from Greek , from kaiein 'to burn' ]
1 . a caustic substance can burn through things by chemical action:
caustic soda (=a chemical used for cleaning things)
2 . a caustic remark criticizes someone in a way that is unkind but often cleverly humorous SYN acerbic
caustic wit/comments/remark etc
Eliot appreciated Pound’s caustic wit.
—caustically /-kli/ adverb :
‘I can hardly wait,’ Sir Trevor replied caustically.