The word 年度 is formed by combining two independent characters, each with its own core meaning, to create a new, composite concept. The first character, 年, means "year", representing the cycle or period of time. The second, 度, carries the fundamental idea of "measurement", "degree", or "extent". When joined, they conceptually frame a year as a specific, measurable unit or standard, leading to the combined sense of "the span of a year as a measured period", used to qualify things like plans, reports, or summaries that are defined by and confined to that yearly cycle.