What word describes the action of being in at one end and out at the other?

The word "through" effectively captures the action of being in at one end and out at the other. It indicates a passage from one side to another, conveying a sense of movement or transition within a space or object. This term is commonly used to describe actions that involve progression, such as walking through a door, moving through a tunnel, or navigating through a process. It clearly encapsulates the idea of entering a space and exiting it at the opposite end.

The other terms do not carry the same meaning: "throught" is not a recognized word in English, "thorough" refers to something done completely and with great attention to detail, while "throughout" suggests something occurring during the entirety of a period or in every part of a place, rather than the movement implied by "through." These distinctions highlight why "through" is the most accurate choice to describe the intended action.