* It's a misspelling: Perhaps you meant a similar-sounding name like "Trina", "Trencia", or "Trincia".
* It's a personal invention: It could be a unique name created by someone.
* It's a place name: There might be a location called Trinicia, but it's not widely known.
To help me understand your intention, could you please provide more context?
For example:
* Where did you encounter the word "Trinicia"?
* What was the context?
* Were you looking for the meaning of a name, a place, or something else?