Answer
There are three known spelling variations for Quintilian's name: Quintilianus, Quintilian, and Quintillian. Quintilianus is the most common spelling, and it is the one that is used in most modern references. Quintilian is a variant spelling that is sometimes used, and Quintillian is a rarer variant that is rarely seen. The three spellings are all derived from the same Latin word, Quintilianus, which means "of Quintilis."