The word "客串" is a compound term formed by combining two characters: "客" (kè), meaning "guest" or "visitor," and "串" (chuàn), which in this context means "to perform" or "to play a role." It is a metaphorical formation where "guest" (客) modifies the action "to perform" (串), creating the meaning of a "guest performance." This describes a situation where someone who is not a regular member of a cast or crew (such as a celebrity from another field or an actor from another production) makes a special, often brief, appearance in a performance, film, or show, thus "stringing along" as a guest. The term encapsulates the concept concisely through this figurative blend of its constituent parts.