SEMIOTICS — [Noun] The systematic study of signs, symbols, and the processes by which they generate meaning. Coined by John Locke from Ancient Greek σημειωτικός (sēmeiōtikós, "fitted for marking, portending"), from σημεῖον (sēmeîon, "a mark, sign, token"). Unlike "semantics," which confines itself to meaning within language, or the archaic "symptomatology," which decodes only medical symptoms, semiotics is the borderless theory of how anything can stand for anything else. It is the red light halting traffic, the unspoken grammar of a raised eyebrow, and the worn smoothness of a stone step—every detail a signifier in a silent world of codes. We are all fluent in a ceaseless conversation of signs, an endless murmuring we are born into but must learn to overhear.