* It's a misspelling: Perhaps you meant "extile" or another word with a similar spelling.
* It's a technical term: It could be a specific term used in a particular field, such as astronomy, mathematics, or a specialized branch of science.
* It's a made-up word: It's possible the word was invented for a specific context or as a creative writing device.
Could you please provide more context?
For example:
* Where did you encounter the word?
* What was the sentence or phrase it was used in?
With more information, I might be able to help you figure out the meaning of "extile."