The compound noun 'water-sharing' is a modern formation built from two deeply rooted English words. 'Water' descends from the Proto-Indo-European wódr̥, a neuter noun for water, which flowed into Proto-Germanic as watōr. 'Share' originates from the Old English scearu, meaning a cutting or division, linked to the act of cutting a portion. The concept logically combines the essential resource ('water') with the action of dividing it ('sharing'), creating a term central to discussions of resource management, diplomacy, and sustainability. Its formation follows the productive English pattern of noun-noun compounding to specify a particular type of sharing arrangement.

Structure: water (liquid) + sharing (distributing) water: From Old English wæter, of Proto-Germanic origin; related to Dutch water and German Wasser. Functions as the primary noun denoting the substance H₂O. sharing: From the verb share, of Old English origin (scearu 'a cutting, division'), combined with the present participle suffix -ing. Functions to indicate the action or concept related to the noun share.