The term "fly handle" doesn't exactly have a widely recognized definition. Unless we consider it in the context of fishing, where it represents a type of reel handle used for casting lines, it becomes clear that antonyms for it would depend on the context it is used in. If we look at the individual words "fly" and "handle," we can think of some potential antonyms that could apply to them. For example, some antonyms for "fly" could be walk, crawl, or swim, while antonyms for "handle" could be mishandle, fumble, or neglect. Again, the specific antonyms for "fly handle" depend on its context of use.