The word 医师 is formed by combining two independent characters, each contributing its core meaning to create a new, composite concept. The first character, 医 (yī), carries the fundamental idea of "healing" or "medicine". It is joined by the second character, 师 (shī), which denotes a "master", "specialist", or "professional". Their union is purely semantic, where 师 acts as a classifier for a person, specifying that the compound refers to "a master of healing", or more directly, a medical doctor or physician. The formation is intuitive, building the term's meaning directly from the sum of its visible parts.