It might be, for example, a word that only appears once in the New Testament, Old Testament, or maybe only once in all of Paul's work, or even in a specific book. Obviously, we will find a higher persentage of hapax legomena if we only look at one of Paul's letters compared to examining all of the Greek in the New Testament in conjunction with the Septuagint (LXX), which is an early translation of the Hebrew Bible into the Koine Greek language used during the time of Jesus and the early Church. The more limited the range, the greater the hapax legomena.
It might seem silly that these words are significant, but at times they can raise interesting insight. We might wonder why the author chose a specific less common word to express an idea. Or it might be that the idea is wrapped up in the unique word itself. This is especially true of words that only appear once in all of the Bible.
Hapax legomena might also raise translational challenges. As one tries to understand how authors were using specific words, he or she can look at how the author used the word elsewhere. Not so with hapax legomena.
An example of a New Testament hapax legomena can be found in Matthew 17:27. Here the word agkistron (translated 'hook') means a bent hook. This is the only place this word is found in the New Testament. Another example, much like the previous one, is agkos (translated 'arm') which means bent arm. This word is found in Luke 2:28. There are over 1,400 hapax legomena and most of them, like a bet hook, are of little concern to the meaning of the passage.