sarcasm vs caustic remark

sarcasm and caustic remark both are nouns.

Word	Noun	Adjective	Verb	Adverb
sarcasm	Yes	No	No	No
caustic remark	Yes	No	No	No

As nouns, sarcasm and caustic remark are synonyms defined as:

sarcasm and caustic remark: witty language used to convey insults or scorn

Other synonyms of sarcasm include irony, satire.

sarcasm (noun)	caustic remark (noun)
witty language used to convey insults or scorn	witty language used to convey insults or scorn