The word 完事 is formed through a direct and logical conceptual combination: the character 完 (wán), meaning "to finish" or "to complete", is placed before 事 (shì), meaning "matter" or "affair". It creates a seamless, cause-and-effect compound where the action of finishing directly modifies the object, the matter, to produce the complete idea of "a matter being finished" or, more naturally, "to be done with something". The formation is akin to a snapshot of a process reaching its conclusion, merging the verb and its object into a single unit that captures the state of completion.