In the English language, antonyms for the phrase "have case" can vary depending on its context. However, certain words that would be considered antonyms may include "lack," "want," or "need." For example, "I do not have a case" would mean "I lack a case" or "I do not need a case." Alternatively, in the legal sense, "have case" may refer to having a legal argument, in which antonyms could include "lose," "forfeit," or "surrender." Regardless of the specific context, antonyms for "have case" typically refer to the opposite of having or possessing something, whether it be tangible or intangible.