What does nat mean in musical terms?

In musical terms, "nat" is an acronym that stands for "natural". It is used in music notation to indicate that a note should be played at its natural pitch, without any alterations such as sharps or flats. The term "natural" can also be used to refer to a note that has been raised or lowered by a semitone, in which case it is usually written as "n". For example, a "C natural" would be the same as a "C", while a "C sharp" would be written as "C#".