What does sarcastic mean?

marked by or given to using irony in order to mock or convey contempt.

Answer: Of, relating to, or characterized by sarcasm.

Using or given to the use of sarcasm.

Sarcasm: harsh or bitter derision or irony.

a sharply ironical taunt; sneering or cutting remark

Explanation: In order to find the definition for sarcastic, we need to find the definition of its root word, sarcasm (definition listed above). Once that is done, we then realize what sarcastic means. Sarcastic is an adjective, while its root word, of course, is a noun. Most adjectives are based off of nouns because they often contain a root word, which is always a noun.