xenna-

The story

1. Ancient Greek · derived fromἐννέα“nine”
2. English todayxenna-

From Ancient Greek ἐννέα (ennéa, “nine”), for the ninth order of 10³, and the letter x, as the third term in a series running backwards through the alphabet (after zetta- and yotta-). The final a conforms to the final vowel of the SI series from mega- upwards.

Words from the same roots