It can be used as:
* An adjective: Describing something as being the only one of its kind.
* A noun: Referring to a unique individual or thing.
Examples:
* "This painting is an unica in the world." (Meaning: This is the only painting of its kind.)
* "She is an unica, a true original." (Meaning: She is a unique and special person.)
The word "unica" is not used as commonly as its English equivalent "unique", but it can be found in some contexts, especially in art, literature, and historical texts.