Punctuality is the state of being prompt. You might come home from a European trip exclaiming over the punctuality of German trains, which are always on time.
Punctuality is an important quality when it comes to things like public transportation and job interviews. If you're known for always showing up exactly when you say you will, people will start to depend on your punctuality. The Latin root of punctuality is punctus, a sharp point. This is why people who value punctuality will tell you to meet them at, say, six o'clock sharp, or right on the dot — in other words, at exactly the agreed-upon time.
