I'll leave this right here : Sarcasm is the caustic use of words, often in a humorous way, to mock someone or something. Sarcasm may employ ambivalence, although it is not necessarily ironic. Most noticeable in spoken word, sarcasm is mainly distinguished by the inflection with which it is spoken or, with an undercurrent of irony, by the extreme disproportion of the comment to the situation, and is largely context-dependent.

Examples of sarcasm and irony used together:

"My you're early!" (After one arrives extremely late).

"What a fine artist you've become!" (When meaning to express displeasure).