"Briny" (adjective, meaning salty or relating to the sea) originated around 1600 from the noun brine (from the Old English bryne or the Middle English brine, meaning water saturated with salt) combined with the adjective-forming suffix -y (from Old English -ig, meaning "full of, covered with, or characterized by").  It often refers to ocean water or anything containing high salt content.  Historically, it was used to describe tears, and is commonly used as a colloquial noun phrase, "the briny," to refer to the ocean or the sea. 

According to the Oxford English Dictionary (OED), the earliest known use of briny as an adjective is in the early 1600s, with evidence dating to 1608 in the writing of T. Davison.  As a noun meaning "the sea," the OED notes its earliest evidence is from the 1830s, specifically 1831 in the work of John Banim.  

The word "briny" is important in stories for creating vivid sensory experiences, immediately evoking the wet, salty, and often atmospheric scent and taste of the sea or preserved foods. It acts as a nostalgic or adventurous descriptor, connecting characters to the natural world, maritime life, or harsh, evocative environments.