From Greek 'kaustikos' (capable of burning) — same root as 'cauterize,' 'calorie,' and 'holocaust' (completely burnt).
Able to burn or corrode organic tissue by chemical action; bitingly sarcastic or critical.
From Latin 'causticus,' from Greek 'kaustikos' (καυστικός, capable of burning, corrosive), from 'kaiein' (καίειν, to burn, to kindle), from PIE *keh₂w- (to burn, to set fire to). The same PIE root produced an extraordinary family of English words: 'cauterize' (to burn a wound shut), 'cauldron' (through Latin 'calidus,' hot, then 'caldāria,' cooking pot), 'calorie' (a unit of heat), 'calid' (warm), 'scald' (via Old Norse from Latin 'calidus'), and 'holocaust' (from Greek 'holokaustos,' ὁλόκαυστος, completely burnt — 'holos' whole + 'kaustos' burnt). The metaphorical sense of 'caustic' speech — words
The word 'calm' is a distant relative of 'caustic' — from Greek 'kauma' (burning heat), through Italian 'calma' (the heat of the day, when everything is still). A calm day was originally a scorchingly hot day when nothing moved, and the word drifted from 'heat-stillness' to 'peace' generally.
Words closest in meaning, ranked by similarity