"Pursuit" originates from the late 14th century Middle English pursuyte or pursuite, derived from Old French poursuite and Anglo-French purseute, signifying a chase or following.  It is rooted in the Vulgar Latin prōsequita, stemming from Latin prōsequī, meaning "to follow, accompany, or pursue".   Originally it meant acting to follow, chase, or overtake someone or something.  While initially focused on physical chasing or persecution, by the 1520s, it developed the sense of "continued exertion" towards an object, leading to the modern definition of a profession, hobby, or quest for a goal.  

According to the Oxford English Dictionary (OED), the earliest known use of the noun pursuit is in the Middle English period (1150-1500), with evidence dating back to 1380.  It originated from Anglo-French (purseute) and was used in the late 14th century, often implying persecution.   The verb pursue appeared slightly earlier, around 1300. 

The concept of pursuit—the active, desire-driven striving of a character toward a goal—is central to storytelling, often considered more crucial than "plot" itself. It acts as the engine that drives action, generates tension, and creates character depth, transforming a mere sequence of events into a compelling narrative.