The man had impenetrable metal skin, incapable of being pierced.
His shield was made of an impenetrable material.
Impenetrable- The fort's defenses were thought to be impenetrable.
His skin was impenetrable, Impenetrable means difficult to get through such as a forest or your skin. the forest was impenetrable and it took me hours to get through.
The professor's heavy accent made the substance of his lecture nearly impenetrable.
Impenetrable is more of an Adjective, it's used to describe a trait, or as in Impenetrable, it's describing how something cannot be penetrated. Penetrate itself would be a verb.
There would be an impenetrable mirror in between.
Around six o'clock, I'll have a great answer for you. Around the fort, our cordon was impenetrable.
The poor man managed to gain passage on board to the ship bound to New York. The impenetrable darkness of the skeleton-lined passage was suddenly lit by a single candle.
I would use it correctly in a sentence, of course. Thank you for asking.
Jarry use paroxysm in a sentence.\
Would not that be "Would not that be?"?
I would use the word "theory" in a sentence like this: "The scientist presented a new theory to explain the findings of the experiment."