"Hast case" is not a commonly used term in the English language. However, the word "hast" could be a typo for "fast." Antonyms for "fast" include slow, unhurried, languid, sluggish, and leisurely. If "hast case" refers to a specific term or phrase, antonyms could vary depending on the intended meaning. Therefore, it is important to clarify the context of the phrase to identify appropriate antonyms. Overall, when looking for antonyms, it is crucial to understand the intended meaning of the term or phrase to accurately identify contrasting words.