* Typo: It could be a misspelling of a real phrase. If you can recall the context, it might be easier to guess the intended word.
* Regional dialect: It might be a phrase specific to a particular region or dialect. Without more information, it's hard to say.
* Made-up phrase: It's possible the phrase is entirely made up, perhaps as a joke or in a fictional context.
Could you please provide more information about where you encountered this phrase, such as:
* The context: Was it spoken, written, or online?
* The language: What language do you think it might be in?
* Any other clues: Do you remember anything else about the situation or the speaker?
With more information, I might be able to help you figure out what "oli impan" means.