A work of art, artwork, objet d'art, or piece of art was a piece of creative work made by an artist. Metaphorically, the term could be used to suggest that something or someone was aesthetically pleasing or well-made.
In 2269, when Droxine and Spock met each other, Droxine stated that she had never met a Vulcan before while Spock, who seemed enamored with her as well, replied by saying he had never met "a work of art" before. (TOS: "The Cloud Minders")