Being on a case refers to the act of investigating or being involved in a particular matter. However, there are several antonyms for this phrase that imply a lack of interest, concern or attention. Some of these antonyms include ignoring, neglecting, disregarding, overlooking, dismissing and abandoning. When someone is ignoring a case, they're choosing to pay no attention to it. Neglecting a case means that they failed to take care of it or give it the necessary attention. Disregarding a case suggests that the matter is unimportant or unworthy of attention. Overlooking a case is to fail to notice or acknowledge it, while dismissing it means to reject or discard it completely. Lastly, abandoning a case implies that someone has given up on investigating it.