The word "仪表" is formed by combining "仪", which conveys concepts of ceremony, ritual, or manner, with "表", which denotes surface, exterior, or the act of showing. This semantic merger results in a compound that originally referred to one's outward appearance and demeanor, encompassing poise and decorum. In modern contexts, the term has extended to mean instruments or meters that display measurements, utilizing "表" in its sense of indication or display. The formation directly integrates the core meanings of each character to create a word with related notions of external manifestation or readable output.