Teachers don't teach? Translators don't translate? You may be be disappointed to learn that the legislative branch legislates. In English, we don't shy away from the repetition, or near-repetition, of a word remotely as much as is customary in German.
What does the executive do? The role of the executive branch varies from country to country. One of its major roles is to ensure the execution of the laws. As I stated above, it does this in large part through various departments and agencies: in the US, for example, through the National Security Agency, the Environmental Protection Agency, the Office of Management and Budget, the Treasury, etc., etc., etc.
Since these departments and agencies can be seen as part of the executive, you could say that the executive branch implements, or puts into practice, the laws passed by the legislature, but in my experience those are not the terms usually used in political science circles.