NEC does not define the term Dedicated Circuit". It does define "Branch Circuit, Individual" which could be construed to be what you are meaning.
Since NEC does not define the term, if it is being used for instance in a specification or on a drawing, then you will need to see what context it is being used in to determine the intent. The term could mean different things to different people.
In general, to me it means that you have a separate breaker feeding an individual load, and if a neutral is involved, there is no sharing between circuits.