Grok is a word that has no direct antonyms. It means to understand or comprehend something intuitively, and there is no opposite to that state of understanding. However, there are several words that can be used as antonyms for grok, depending on the context. Words such as confuse, misunderstand, ignore, flounder, and perplex are some of the possible antonyms that can be used to describe someone who is struggling to grasp a concept or failing to understand something completely. In other words, these are the words that describe the opposite of grok, which is the failure to understand something intuitively.