'one-of-a-kind' originates from the phrase 'one of a kind,' where 'one' signifies singularity and 'kind' refers to a category or type.

The phrase 'one of a kind' has been used in English since the 19th century to denote something unique or unparalleled.

Initially, it meant 'one belonging to a specific category,' but over time it evolved to emphasize uniqueness.