Unique Meaning In English. It either is unique or it is not and there are no stages in between. Un systme unique a single system.
In practice the situation in the language is more complex than this. Existing as the only one or as the sole example. Being the only existing one of its type or more generally unusual or special in some way.
Usage note for unique.
1 of relating to or belonging to a single person. Being the only existing one of its type or more generally unusual or special in some way. It either is unique or it is not and there are no stages in between. Of a feature such that only one holder has it.