also: ねんげつ
noun
months and years; time; passage of time
Refers to the flow or accumulation of time, often with a sense of duration or the weight of passing years. Common in expressions like 年月が経つ (time passes).
年月が経つのは早いものだ。
How quickly the months and years go by.
長い年月をかけてこの技術は
This technology has developed over many years.