A subset of a metric space is clopen iff it is both closed and open. A metric space is called zero-dimensional iff there is a base for the open sets consisting of clopen sets.

Despite a mediocre grade in English, Pat just managed to sneak in to the university.

The company had engineered plenty of products, but manufacturing them was virgin territory.

There was no road, nor any wood-man’s path, But the thick umbrage, checking the wild growth Of weed and sapling […]