It's possible you meant a similar word like:

* Impassable: This is a term used to describe something that cannot be passed through, often referring to physical barriers like a dense forest or a blocked road.

* Impenetrable: Similar to "impassable", this term describes something that cannot be penetrated, often referring to physical materials like a strong metal or a thick wall.

* Impermeable: This is a more specific term referring to a material that does not allow fluids to pass through it. For example, a raincoat is impermeable to water.

It's important to be precise with scientific terminology to ensure clear communication and understanding. If you can provide more context or the full sentence where you encountered this word, I might be able to help you figure out the intended meaning.