The word 摇摇欲坠 is formed by the reduplication of the character 摇 (meaning to shake) to create 摇摇, emphasizing continuous or intense shaking. This is directly combined with 欲 (meaning about to) and 坠 (meaning to fall), resulting in a literal sequence that conveys "shaking repeatedly and about to fall", thus expressing the state of being on the verge of collapse.