unique identifier
Computing term for a value that uniquely identifies an entity, such as a database key or a UUID.
See also: 一意
In a database, a unique identifier is assigned to each record.
一意 means 'unique' or 'one meaning' and is used as a modifier in compounds like 一意な識別子; it is not a standalone noun for 'identifier'.
Compound of 一意 (unique) + な (attributive) + 識別子 (identifier). A modern technical term, likely a calque from English 'unique identifier'.