It's possible that:
* It's a misspelling: Perhaps it's a misspelling of a similar word, like "entrances" or "occurrences".
* It's a proper noun: It could be a person's name, a place name, or a specific term from a particular field or language.
* It's a made-up word: Some authors or creators invent words for their own purposes.
To understand what "ortrances" means, you need more context. Please provide more information about where you encountered this word. For example:
* What was the sentence or text it was in?
* What was the subject or topic being discussed?
* Was it in a book, article, conversation, or online source?
With more context, I can help you figure out what "ortrances" might mean.