The compound "time-stream" is a modern English formation, combining two deeply rooted Germanic words to create a powerful metaphor. "Time," from Old English tīma, is related to the Proto-Germanic tīmô, which carried the sense of a fitting or proper season. "Stream," from Old English strēam, originates from the Proto-Germanic straumaz, meaning a flowing current, itself from the Proto-Indo-European root sreu- "to flow." The logic of the compound lies in applying the tangible, directional, and continuous imagery of a flowing river to the abstract and relentless progression of time. This conceptual blend, popularized in 20th-century science fiction, elegantly frames time not as a series of discrete points but as a navigable and sometimes branching continuum, giving physicality to a philosophical idea.

Structure: time (period) + stream (flow) - time: From Old English 'tīma', meaning a period, season, or era. Its functional role is as the primary noun root, specifying the subject matter. - stream: From Old English 'strēam', meaning a current or flow of water. Its functional role is as the modifying noun, creating a compound that metaphorically describes the nature of the primary noun.