The Chinese idiom 无懈可击 (wú xiè kě jī) is formed through a classical four-character structure where the first two and last two characters create a logical, cause-and-effect relationship. Literally, 无懈 means "having no laxity" or "no weakness," and 可击 means "can be attacked." However, the idiom functions as a double negation; it describes a state where, because there is no flaw or slackness (无懈), there is no point or opportunity that can be attacked (可击). Thus, the combined meaning is "flawless," "impregnable," or "unassailable," often used to describe an argument, defense, or plan that is so perfect it leaves no opening for criticism or attack.