The word "心肝" (xīn gān) is formed through semantic compounding, combining the characters for "heart" (心) and "liver" (肝), the two organs traditionally considered the most vital and central to life in Chinese medicine and philosophy. This combination creates a metaphor where the essential, internal organs represent something of utmost importance and emotional depth. Consequently, the term evolved to mean "darling" or "treasure," used as a term of endearment for a beloved person (especially a child or romantic partner), as they are held as dearly as one's own life. The formation exemplifies how Chinese often creates abstract, affectionate meanings by pairing concrete, bodily terms to express intimate value and emotional core.