"Unbridgeable" Natural Recordings by Native Speakers
Imperceptibly exceeding the limits of understanding, thought, or knowledge; insurmountable.
Not having a manufacturer's or vendor's name or logo on a product, often indicating it is generic or a store brand.
Meaning: not allowing air to be breathed through; unsuitable or unhealthy to breathe in; not permeable to air.<br><br>Example: "The unbreathable air in the factory made it difficult for workers to breathe."