The word 'unpack' is a transparent English formation built from the Germanic verb 'pack' and the reversative prefix 'un-'. The core verb 'pack' entered English from Middle Dutch, carrying the sense of bundling or stowing items into a container. By attaching the Old English prefix 'un-', which denotes the reversal or undoing of an action, the compound verb logically means to undo the act of packing—to take items out. This literal meaning later extended metaphorically to the intellectual process of taking apart or analyzing a complex idea, argument, or piece of information into its constituent elements.

Structure: un (reverse action) + pack (to put into a container) - un: A prefix of Germanic origin (Old English un-, on-), meaning "not" or "reverse of an action." In this word, it functions as a reversative prefix. - pack: A verb of Germanic origin (Middle Dutch pak, pakken), meaning "to put together into a bundle or container." It functions as the root verb denoting the action being reversed.