The word "仪器" is formed by combining two characters, each contributing a layer of meaning to create a new concept. The first character, "仪" (yí), originally carried meanings related to ritual, ceremony, standard, or proper demeanor, which evolved to imply something used for measurement, observation, or establishing a standard. The second character, "器" (qì), has a fundamental meaning of "vessel", "utensil", or "tool". When fused together, "仪器" conceptually merges the idea of a "tool for measurement or observation" (from 仪) with the general notion of a "physical apparatus or device" (from 器), resulting in the modern meaning of "instrument" or "apparatus", specifically referring to precision tools for scientific or technical purposes.