Kissoff, an informal term meaning rejection or dismissal, can have several antonyms depending on the intended context. If the opposite of kissoff is a welcome, then words such as greeting, embrace, or acceptance would be possible antonyms. On the other hand, if kissoff is to be taken as an ending or conclusion, then antonyms could include continuation, extension, or renewal. Similarly, if kissoff is interpreted as a negative outcome, its antonyms could be positive merits such as success, achievement, or victory. Ultimately, the exact antonym of Kissoff would depend on the context in which the word is used.