The word **颠覆 (diānfù)** is a compound formed by combining two characters with closely related meanings to create a powerful metaphorical verb. The first character, **颠 (diān)**, originally meant the top of the head or summit, and by extension carries the sense of "topple" or "fall from a height." The second, **覆 (fù)**, means "to overturn," "capsize," or "cover." When combined, their literal sense is "to overturn and topple over," vividly depicting something being turned completely upside down. This concrete image is then applied abstractly to mean **"to subvert," "overthrow,"** or **"completely upend"** an established system, authority, or idea, emphasizing a fundamental and catastrophic reversal. It is a classic example of Chinese morphological formation where two synonymous or complementary roots unite to reinforce a single, intensified concept.