Sarcastic means saying the opposite of what you mean, in order to wound. Lovely weather, said in a downpour.
The intention to hurt is what separates sarcasm from irony, which can be entirely good-natured. Tone carries almost all of it, which is why sarcasm travels so badly in writing and causes so many arguments by message. British English is famously fond of it. The noun is sarcasm, and the old line about it being the lowest form of wit has never stopped anybody. The adverb sarcastically is a favourite in dialogue tags.
1adjectivesarcasticSaying the opposite of what is meant, in order to mock or wound.
“There is no need to be sarcastic about it.”
French
sarcastique
English, today
sarcastic
From sarcasm + -astic. Either from sarcasm + astic or from French sarcastique, from French sarcasme, from Latin sarcasmus, ultimately from Ancient Greek σαρκασμός (“sarcasm”), itself from Ancient Greek σάρξ literally “meat, flesh”.
Etymology from Wiktionary, CC BY-SA