When it comes to having something "gat down pat," you have it mastered. In other words, you have become so proficient at it that it has become second nature. There are numerous synonyms for this phrase, such as "have it down cold," "have it down to a science," "have it off to a tee," and "have it wired." All of these phrases communicate the idea of having something completely under control and being able to execute it flawlessly. Having something "gat down pat" can apply to anything from a skill to a task, and it is a sure sign of expertise and experience.