A subplot is a smaller storyline within a larger narrative. However, there are other terms that can be used interchangeably with this word to convey a similar meaning. For instance, a "side story" can refer to a subplot that adds layers of complexity to the main plot. A "secondary plot" also serves as a narrative thread that may involve different characters or settings. On the other hand, a "subtheme" implies that the subplot expands on or complements a central theme of the story. Regardless of the term used, a well-executed subplot can enhance the overall story by adding depth and nuance to the characters and their motivations.