important, vital, want

要 is composed of a variant of 𦥑 (two hands) and 女 (woman). It conveys the idea of a woman with both hands placed on her slender waist. Its original meaning is the waist, but this sense was later taken over by the character 腰. The waist is the main pivot of the human body that connects the upper and lower parts. Therefore, 要 is used to mean key, crucial, or important.